Let A = {a, b, c, d} and B = {x, y, z}. Which of the following are relations from A to B ? -Maths 9th

Let A = {a, b, c, d} and B = {x, y, z}. Which of the following are relations from A to B ? -Maths 9th
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1 Answer

Answer :

(i) Yes. (ii) No, because in the ordered pair (a, d), a ∈ A and d ∉ B. (iii) No, because in (y, d), y ∈ B. (iv) No. because here the first entries in all the ordered pairs are in the set B. (v) No. (vi) No, because the element z is not an ordered pair. (vii) No, because the elements of the set are not ordered pairs.
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Related questions

Which of the following are relations from B to A where A = {a, b, c, d} and B = {x, y, z}? -Maths 9th

Description : Which of the following are relations from B to A where A = {a, b, c, d} and B = {x, y, z}? -Maths 9th

Last Answer : (c) (i), (ii) and (iv)The set of ordered pairs {(b, y), (z, a), (x, c)} does not state a relation from B to A as the ordered pair (b, y) has the first element ‘b’ from set A, whereas it should be from set B.

Let A = {2, 3, 5, 6}. Then, which of the following relations is transitive only? -Maths 9th

Description : Let A = {2, 3, 5, 6}. Then, which of the following relations is transitive only? -Maths 9th

Last Answer : (d) R = {(2, 3), (3, 5), (2, 5)}.

Let x be the mean of x1, x2,….,xn and y be the mean of y1, y2, ……,yn the mean of z is x1, x2,….,xn , y1, y2, ……,yn then z is equal to -Maths 9th

Description : Let x be the mean of x1, x2,….,xn and y be the mean of y1, y2, ……,yn the mean of z is x1, x2,….,xn , y1, y2, ……,yn then z is equal to -Maths 9th

Last Answer : NEED ANSWER

Let x be the mean of x1, x2,….,xn and y be the mean of y1, y2, ……,yn the mean of z is x1, x2,….,xn , y1, y2, ……,yn then z is equal to -Maths 9th

Description : Let x be the mean of x1, x2,….,xn and y be the mean of y1, y2, ……,yn the mean of z is x1, x2,….,xn , y1, y2, ……,yn then z is equal to -Maths 9th

Last Answer : According to question find the value of z

Consider the following relations R = {(x, y) | x, y are real numbers and x = wy for some rational number w}; -Maths 9th

Description : Consider the following relations R = {(x, y) | x, y are real numbers and x = wy for some rational number w}; -Maths 9th

Last Answer : (c) S is an equivalence relation but R is not an equivalence relationR = {(x, y) | x, y ∈ R, x = wy, w is a rational number} Reflexive: x R x ⇒ x = wx ⇒ w = 1, (a rational number) Hence R is reflexive. Symmetric ... \(rac{r}{s}\) ⇒ \(rac{m}{n}\) S \(rac{r}{s}\) (True)∴ S is an equivalence relation.

Let x and y be rational and irrational numbers, respectively. -Maths 9th

Description : Let x and y be rational and irrational numbers, respectively. -Maths 9th

Last Answer : Yes, (x + y) is necessarily an irrational number.

Let x be rational and y be irrational. Is xy necessarily irrational? Justify your answer by an example. -Maths 9th

Description : Let x be rational and y be irrational. Is xy necessarily irrational? Justify your answer by an example. -Maths 9th

Last Answer : No, (xy) is necessarily an irrational only when x ≠0. Let x be a non-zero rational and y be an irrational. Then, we have to show that xy be an irrational. If possible, let xy be a rational number. Since ... wrong. Hence, xy is an irrational number. But, when x = 0, then xy = 0, a rational number.

Let y varies directly as x. If y = 12 when x = 4, then write a linear equation. What is value of y when x = 5 ? -Maths 9th

Description : Let y varies directly as x. If y = 12 when x = 4, then write a linear equation. What is value of y when x = 5 ? -Maths 9th

Last Answer : Linear equation

Let x and y be rational and irrational numbers, respectively. -Maths 9th

Description : Let x and y be rational and irrational numbers, respectively. -Maths 9th

Last Answer : Yes, (x + y) is necessarily an irrational number.

Let x be rational and y be irrational. Is xy necessarily irrational? Justify your answer by an example. -Maths 9th

Description : Let x be rational and y be irrational. Is xy necessarily irrational? Justify your answer by an example. -Maths 9th

Last Answer : No, (xy) is necessarily an irrational only when x ≠0. Let x be a non-zero rational and y be an irrational. Then, we have to show that xy be an irrational. If possible, let xy be a rational number. Since ... wrong. Hence, xy is an irrational number. But, when x = 0, then xy = 0, a rational number.

Let y varies directly as x. If y = 12 when x = 4, then write a linear equation. What is value of y when x = 5 ? -Maths 9th

Description : Let y varies directly as x. If y = 12 when x = 4, then write a linear equation. What is value of y when x = 5 ? -Maths 9th

Last Answer : Linear equation

Let cost of a pen and a pencil be “x” and “y” respectively. A girl pays ₹16 for 2 pens and 3 pencils. Write the given data in the form of a linear equation in two variables. Also represent it graphically. -Maths 9th

Description : Let cost of a pen and a pencil be “x” and “y” respectively. A girl pays ₹16 for 2 pens and 3 pencils. Write the given data in the form of a linear equation in two variables. Also represent it graphically. -Maths 9th

Last Answer : Solution :-

Let R be a relation from A = {1, 2, 3, 4, 5, 6} to B = {1, 3, 5} which is defined as “x is less than y”. -Maths 9th

Description : Let R be a relation from A = {1, 2, 3, 4, 5, 6} to B = {1, 3, 5} which is defined as “x is less than y”. -Maths 9th

Last Answer : R = {a, b : a < b, a ∈ A, b ∈ B}, where A = {1, 2, 3, 4, 5, 6} and B = {1, 3, 5}. ∴ R = {(1, 3), (1, 5), (2, 3), (2, 5), (3, 5), (4, 5)} Domain of R = {1, 2, 3, 4} Range of R = {3, 5} Codomain of R = {1, 3, 5}.

Let X be the set of all graduates in India. Elements x and y in X are said to be related, if they are graduates of the same university. -Maths 9th

Description : Let X be the set of all graduates in India. Elements x and y in X are said to be related, if they are graduates of the same university. -Maths 9th

Last Answer : R = {(x, y)}: x and y are graduates of same university, x, y ∈ {All graduates of India}. R is reflexive as (x, x) ∈ R, since x and x are graduates from the same university. R ... graduates from the same university ⇒ (x, z) ∈ R. R being reflexive, symmetric and transitive is an equivalence relation.

Let R be a relation on the set N, defined by {(x, y) : 2x – y = 10} then R is -Maths 9th

Description : Let R be a relation on the set N, defined by {(x, y) : 2x – y = 10} then R is -Maths 9th

Last Answer : (a) ReflexiveGiven, {(\(x\), y) : 2\(x\) – y = 10} Reflexive, \(x\) R \(x\) = 2\(x\) – \(x\) = 10 ⇒ \(x\) = 10 ⇒ y = 10 ∴ Point (10, 10) ∈ N ⇒ R is reflexive.

Let ABCD be a quadrilateral. Let X and Y be the mid-points of AC and BD respectively and the lines through X and Y respectively -Maths 9th

Description : Let ABCD be a quadrilateral. Let X and Y be the mid-points of AC and BD respectively and the lines through X and Y respectively -Maths 9th

Last Answer : answer:

Let R and S be two fuzzy relations defined as: Image Then, the resulting relation, T, which relates elements of universe x to elements of universe z using max-min composition is given by

Description : Let R and S be two fuzzy relations defined as: Then, the resulting relation, T, which relates elements of universe x to elements of universe z using max-min composition is given by

Last Answer : Answer: C

Define the types of relations and their examples. -Maths 9th

Description : Define the types of relations and their examples. -Maths 9th

Last Answer : There are various types of relations:Let A be a non-empty set. Then, a relation R on A is said to be Reflexive if (a, a) ∈ R for each a ∈ A, i.e., if a R a for each a ∈ A. For example, the relation is as strong as is reflexive ... a || b ⇒ b || a a || b, b || c ⇒ a || c.

Determine the domain and range of the following relations: (i) {(–3, 1), (–1, 1), (1, 0), (3, 0)} -Maths 9th

Description : Determine the domain and range of the following relations: (i) {(–3, 1), (–1, 1), (1, 0), (3, 0)} -Maths 9th

Last Answer : (i) Domain = {-3, -1, 1, 3}, Range = {0, 1} (ii) Domain = {x : x is a multiple of 3} = {3n : n ∈ Z} Range = {y : y is a multiple of 5} = {5n : n ∈ Z} (iii) Relation = {(x, x2) : x is a prime number ... (7, 49), (11, 121), (13, 169)} Domain = {2, 3, 5, 7, 11, 13}, Range = {4, 9, 25, 49, 121, 169}

I is the set of integers. Describe the following relations in words, giving its domain and range. -Maths 9th

Description : I is the set of integers. Describe the following relations in words, giving its domain and range. -Maths 9th

Last Answer : R = {(0, 0), (1, – 1), (2, – 2), (3, – 3) ...} = {(x, y) : y = – x, x ∈ W} Domain = {0, 1, 2, 3, ....} = W, Range = {...,– 3, – 2, – 1, 0}

Write ‘yes’ if each of the following relations is an equivalence relation. -Maths 9th

Description : Write ‘yes’ if each of the following relations is an equivalence relation. -Maths 9th

Last Answer : (i) is parallel to' is reflexive, because any line is parallel to itself. Symmetric, because if line l is parallel to line m, then line m is parallel to line l. Transitive, because if l || m ... y cannot be a factor of x. (v) No, because the relation is reflexive and transitive but not symmetric.

Given A = {–2, –1, 0, 1, 2}, which of the following relations on A have both domain and range equal to A? -Maths 9th

Description : Given A = {–2, –1, 0, 1, 2}, which of the following relations on A have both domain and range equal to A? -Maths 9th

Last Answer : (d) (i) and (iii)Let us examine the domain and range of the each relation individually: (i) R : is equal to means R = {(a, b) : a = b, a ∈ A, b ∈A} ∴ R = {(-2, -2), (-1, -1), (0, 0), (1, ... = {-2, -1, 0, 1} and range = {-1, 0, 1, 2}. ∴ Relations given in (i) and (iii) satisfy the given condition.

If n(A) = 5 and n(B) = 7, then the number of relations on A × B is -Maths 9th

Description : If n(A) = 5 and n(B) = 7, then the number of relations on A × B is -Maths 9th

Last Answer : (b) 235n(A) = 5 and n(B) = 7 ∴ n(A × B) = 5 × 7 = 35 Total number of relations from A to B = Total number of subsets of (A × B) = 235.

Which of the following relations is only symmetric? -Maths 9th

Description : Which of the following relations is only symmetric? -Maths 9th

Last Answer : (c) “is perpendicular to” on a set of a coplanar lines(a) Let a, b, c ∈ A where A is a set of real numbers. Then R = {(a, b) : a ≤ b, a, b ∈ A} is : Reflexive: a ≤ a ⇒ (a, a) ∈ R (Yes) Symmetric: a ≤ b ⇒ (a, b) ∈ R, but a ≤ b ⇒ a < b or a = b ⇒ b = a but b \( ot

If R is a relation on a finite set A having n elements, then the number of relations on A is -Maths 9th

Description : If R is a relation on a finite set A having n elements, then the number of relations on A is -Maths 9th

Last Answer : (d) \(2^{n^2}\)Set A has n elements ⇒ n(A) = n ⇒ A × A has n × n = n2 elements ∴ Number of relations on A = Number of subsets of A × A = \(2^{n^2}\)

If x+y=10 and x=z then show that z+y=10 by using appropriate eculids axioms? -Maths 9th

Description : If x+y=10 and x=z then show that z+y=10 by using appropriate eculids axioms? -Maths 9th

Last Answer : This answer was deleted by our moderators...

If x+y =10 and x=z then show that z+y =10 -Maths 9th

Description : If x+y =10 and x=z then show that z+y =10 -Maths 9th

Last Answer : It is given that x+y =10 Also x= z Therefore, x+y =10 Z+y =10 ( x = z)

In the following equations , find which of the variables x, y, z etc. represent rational numbers and which represent irrational numbers -Maths 9th

Description : In the following equations , find which of the variables x, y, z etc. represent rational numbers and which represent irrational numbers -Maths 9th

Last Answer : Following are the rational numbers which represent irrational numbers .

X and y are points on the side LN of the triangle LMN , such that LX = XY = YN . Through X, a line is drawn parallel to LM to meet MN at Z. -Maths 9th

Description : X and y are points on the side LN of the triangle LMN , such that LX = XY = YN . Through X, a line is drawn parallel to LM to meet MN at Z. -Maths 9th

Last Answer : Here, △XZM and △XZL are on the same base (XZ) and lie between the same parallels (XZ || LM). ∴ ar(△XZL) = ar( △XZM) Adding ar(△XZY) on both sides , we have ar(△XZL) + ar(△XZY) = ar(△XZM) + ar(△XZY) ⇒ ar(△LZY) = ar(quad.MZYX)

A bag contains x white, y red and z blue balls. -Maths 9th

Description : A bag contains x white, y red and z blue balls. -Maths 9th

Last Answer : Number of blue balls = z Total balls = x + y + z therefore P(blue ball)= z /(x+y+z )

Find which of the variables x, y, z and u represent rational numbers and which irrational numbers. -Maths 9th

Description : Find which of the variables x, y, z and u represent rational numbers and which irrational numbers. -Maths 9th

Last Answer : Rational number and irrational number

If x+y=10 and x=z then show that z+y=10 by using appropriate eculids axioms? -Maths 9th

Description : If x+y=10 and x=z then show that z+y=10 by using appropriate eculids axioms? -Maths 9th

Last Answer : This answer was deleted by our moderators...

If x+y =10 and x=z then show that z+y =10 -Maths 9th

Description : If x+y =10 and x=z then show that z+y =10 -Maths 9th

Last Answer : It is given that x+y =10 Also x= z Therefore, x+y =10 Z+y =10 ( x = z)

In the following equations , find which of the variables x, y, z etc. represent rational numbers and which represent irrational numbers -Maths 9th

Description : In the following equations , find which of the variables x, y, z etc. represent rational numbers and which represent irrational numbers -Maths 9th

Last Answer : Following are the rational numbers which represent irrational numbers .

X and y are points on the side LN of the triangle LMN , such that LX = XY = YN . Through X, a line is drawn parallel to LM to meet MN at Z. -Maths 9th

Description : X and y are points on the side LN of the triangle LMN , such that LX = XY = YN . Through X, a line is drawn parallel to LM to meet MN at Z. -Maths 9th

Last Answer : Here, △XZM and △XZL are on the same base (XZ) and lie between the same parallels (XZ || LM). ∴ ar(△XZL) = ar( △XZM) Adding ar(△XZY) on both sides , we have ar(△XZL) + ar(△XZY) = ar(△XZM) + ar(△XZY) ⇒ ar(△LZY) = ar(quad.MZYX)

A bag contains x white, y red and z blue balls. -Maths 9th

Description : A bag contains x white, y red and z blue balls. -Maths 9th

Last Answer : Number of blue balls = z Total balls = x + y + z therefore P(blue ball)= z /(x+y+z )

Find which of the variables x, y, z and u represent rational numbers and which irrational numbers. -Maths 9th

Description : Find which of the variables x, y, z and u represent rational numbers and which irrational numbers. -Maths 9th

Last Answer : Rational number and irrational number

if xylogxy/x+y, yzlogyz/y+z and zxlogzx/z+x are mutually equal, then show that x^x= y^y=z^z -Maths 9th

Description : if xylogxy/x+y, yzlogyz/y+z and zxlogzx/z+x are mutually equal, then show that x^x= y^y=z^z -Maths 9th

Last Answer : NEED ANSWER

if xylogxy/x+y, yzlogyz/y+z and zxlogzx/z+x are mutually equal, then show that x^x= y^y=z^z -Maths 9th

Description : if xylogxy/x+y, yzlogyz/y+z and zxlogzx/z+x are mutually equal, then show that x^x= y^y=z^z -Maths 9th

Last Answer : This answer was deleted by our moderators...

Using factor theorem,show that (x-y) is a factor of x(y(square) - z(square)) + y(z(square) - x(square)) + z(x(square) - y(square) ) -Maths 9th

Description : Using factor theorem,show that (x-y) is a factor of x(y(square) - z(square)) + y(z(square) - x(square)) + z(x(square) - y(square) ) -Maths 9th

Last Answer : Solution :-

It is known that if x+y =10, then x+y+z = 10+z.Which axiom of Euclids does this statement illustrate? -Maths 9th

Description : It is known that if x+y =10, then x+y+z = 10+z.Which axiom of Euclids does this statement illustrate? -Maths 9th

Last Answer : Solution :- Second axiom.

In Fig. 6.14, if x+y = w+z,then then prove that AOB is a line. -Maths 9th

Description : In Fig. 6.14, if x+y = w+z,then then prove that AOB is a line. -Maths 9th

Last Answer : Solution :-

In the Fig.8.11. ABCD is a parallelogram.what is the sum of angles x,y and z? -Maths 9th

Description : In the Fig.8.11. ABCD is a parallelogram.what is the sum of angles x,y and z? -Maths 9th

Last Answer : Solution :-

In Fig. 8.28, ABCD is a parallelogram. Find the value of x, y and z. -Maths 9th

Description : In Fig. 8.28, ABCD is a parallelogram. Find the value of x, y and z. -Maths 9th

Last Answer : Solution :-

If (log x)/(l + m - 2n) = (log y)/(m + n - 2l) = (log z)/(n + l - 2m), then xyz is equal to : -Maths 9th

Description : If (log x)/(l + m - 2n) = (log y)/(m + n - 2l) = (log z)/(n + l - 2m), then xyz is equal to : -Maths 9th

Last Answer : Let l+m−2nlogx​=m+n−2llogy​=n+l−2mlogz​=k(say) So, we get logx=k(l+m−2n) ....... (i) logy=k(m+n−2l) ....... (ii) logz=k(n+l−2m) ....... (iii) ∴logx+logy+logz=k(l+m−2n)+k(m+n−2l)+k(n+l−2m) ⇒logx+logy+logz=kl+km−2kn+km+kn−2kl+kn+kl−2km ⇒log(xyz)=0 ⇒logxyz=log1 ⇒xyz=1

If x = logabc, y = logbca, z = logc ab, then -Maths 9th

Description : If x = logabc, y = logbca, z = logc ab, then -Maths 9th

Last Answer : (a) x + y + z + 2 = xyz.x = logabc ⇒ ax = bc ⇒ ax + 1 = abc ⇒ a = (abc)1/(x +1) Similarly, b = (abc)1/(y + 1), c = (abc)1/(z + 1)∴ abc = \((abc)^{rac{1}{x+1}+rac{1}{y+1}+rac{1}{z+1}}\)⇒ \({rac{1}{x+1}+ ... + xz + x + z + 1 + xy + y + x + 1 = xyz + xy + yz + zx + x + y + z + 1⇒ x + y + z + 2 = xyz.

If y = (1/(a^(1-loga x))), z = (1/(a^(1-loga y))) and x = a^k, then k = -Maths 9th

Description : If y = (1/(a^(1-loga x))), z = (1/(a^(1-loga y))) and x = a^k, then k = -Maths 9th

Last Answer : (b) \(rac{1}{{1-log_az}}\) y = \(rac{1}{a^{1-log_ax}}\) = \(a^{-(1-log_ax)}\)⇒ logay = \(rac{1}{{1-log_ax}}\) and loga z = \(rac{1}{{1-log_ay}}\)∴ logaz = \(rac{1}{1-\bigg(rac{1}{1-log_ax}\bigg)}\) = \( ... x = \(rac{1}{{1-log_az}}\)⇒ x = \(a^{rac{1}{1-log_az}}\) = ak ⇒ k = \(rac{1}{{1-log_az}}\).

If x, y, z are distinct positive numbers different from 1, such that -Maths 9th

Description : If x, y, z are distinct positive numbers different from 1, such that -Maths 9th

Last Answer : (d) 1logy x. logz x - logx x = \(rac{ ext{log}\,x}{ ext{log}\,y}\) . \(rac{ ext{log}\,x}{ ext{log}\,z}\) - 1 = \(rac{ ext{(log}\,x^2)}{ ext{log}\,y.\, ext{log}\,z}\) - 1Similarly, logx y.logz y - logy y = ... log z = 0 (if a + b + c = 0, then a3 + b3 + c3 = 3abc) ⇒ log xyz = 0 ⇒ xyz = 1.

If (log x)/(a^2+ab+b^2) = (log y)/(b^2+bc+c^2) = (log z)/(c^2+ca+a^2), then x^(a-b). y^(b-c). z^(c-a) = -Maths 9th

Description : If (log x)/(a^2+ab+b^2) = (log y)/(b^2+bc+c^2) = (log z)/(c^2+ca+a^2), then x^(a-b). y^(b-c). z^(c-a) = -Maths 9th

Last Answer : (c) 1Let each ratio = k and base = e ⇒ loge x = k(a2 + ab + b2) ⇒ (a - b) loge x = k (a - b) (a2 + ab + b2) ⇒ loge xa - b = k(a3 - b3) ⇒ xa - b = \(e^{k(a^3-b^3)}\) Similarly, yb-c = \(e^{k(b^3-c^3)}\), zc-a = \ ... (e^{k(b^3-c^3)}\) . \(e^{k(c^3-a^3)}\)= \(e^{k[a^3-b^3+b^3-c^3+c^3-a^3]}\) = e0 = 1.

If x, y, z are in G.P. and (log x – log 2y), (log 2y – log 3z) and (log 3z – log x) are in A.P., -Maths 9th

Description : If x, y, z are in G.P. and (log x – log 2y), (log 2y – log 3z) and (log 3z – log x) are in A.P., -Maths 9th

Last Answer : (d) obtuse angledx, y, z are in G.P. ⇒ y2 = xz ...(i) (log x - log 2y), (log 2y - log 3z) and (log 3z - log x) are in A.P. ⇒ 2(log 2y - log 3z) = (log x ... x is the length of the side opposite ∠A.∵ cos A is less than 0, i.e, negative, ∠A is obtused and the triangle is obtuse angled.