If α + β = 90° and α = 2β then cos α equal: (a) 1 (b) zero (c) 1/2 (d) 2

If α + β = 90° and α = 2β then cos α equal:
(a) 1
(b) zero
(c) 1/2
(d) 2
by

1 Answer

Answer :

(c) 1/2
by

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