Question

Given that cos 63°≈ 0.454, enter the sine of a complementary angle.
sin

Answer 1

`\cos(63^\circ)` is the same as
`\sin(27^\circ)` by co-function identities

Explanation:

Remember that complementary angles add up to 90°. The angle that i s complementary to 63° is 27°.

Also recall the co-function identities:

• sin (90° – x) = cos x
• cos (90° – x) = sin x

This means that
`\cos(90^\circ-27^\circ)=\sin(27^\circ)\approx0.454`.