Question

Which statement is true?

In any right triangle, the sine of one acute angle is equal to the cosine of the other acute angle.

In any right triangle, the sine of one acute angle is equal to the sine of its complementary angle.

In any right triangle, the cosine of one acute angle is equal to the cosine of its complementary angle.

In any right triangle, the sum of the sine of one acute angle and the cosine of the other acute angle is 1.

Answer 1

Sine and Cosine are co-functions where the "co" comes from complementary angles.
So, there is a tie-in to complementary for Sine and Cosine.

Answer 2

I'm going to post the cofunction identity for sine and cosine here for you to study.

Answer 3

Two angles that sum to 90 are complementary. So, x and (90-x) are complementary angles and are acute.

Applying the cofunction identity for sine and cosine that is attached above, which option do you think is correct?

@SDS

Answer 4

the last one?

Answer 5

No. I forgot to say that the acute angles of a right triangle are complementary.
Knowing that and the cofunction identity gives this as the answer:

In any right triangle, the sine of one acute angle is equal to the cosine of the other acute angle.

Answer 6

Question?

Answer 7

no