Question

Find the value of the acute angle for which cos=sin(theta-20)

Answer 1

I know the answer is 55 degrees, I just dont understand why!

Answer 2

its the identity
\[\cos x = \sin (90-x)\]
if the 2 angles add up to 90...then sin = cos
therefore
x + (x-20) = 90
--> x = 55

Answer 3

thanks!

Answer 4

yw