Question

Let ∠X and ∠Y be complementary. If sin(X) =
3
5
and cos(X) =
4
5
, then what is the value of sin(Y)?

Answer 1

Answer:

sin(Y) = 4/5

Step-by-step explanation:

The sine of one of a pair of complementary angles is equal to the cosine of the other. Given that ∠X and ∠Y are complementary, sin(Y) = cos(X) = 4/5.

_____

You can figure this from SOH CAH TOA, the mnemonic that reminds you of the definitions of the trig functions. The adjacent leg for one of the acute angles in the right triangle is the opposite leg for the other angle.

... Sin = Opposite/Hypotenuse

... Cos = Adjacent/Hypotenuse