Question

5.) Write the trigonometric function Sin 64° in terms of its co-function.

a) Cos (64°)
b) Cos (116°)
c) Cos (26°)
d) Cos (46°)

Answer 1

Cos(26)


because

Sin(x) = Cos(90 - x)
and
Cos(x) = Sin(90 - x)

Answer 2

so...sin (90-theta) = cos theta

so.... sin 64= sin(90-26)
=>cos 26

so the answer is C