Question

Express cos 71° - sin 57° + tan 63° in terms of trigonometric ratios of angles between 0° and 45°.

Answer 1

We know that sinA = cos(90-A) & cosA= sin(90-A)
Simiraly answer goes sin 19 - cos 33 +cot 27

Answer 2

HEYA....✌✌✌✌

HERE IS YOUR ANSWER.......

Cos@=sin(90-@)
Cos71=sin(90-71)
===>>>sin19

Sin@=cos(90-@)
Sin59=cos(90-59)
===>>>>cos31

So sin19-cos31 is between 0° to 45°
Hence proved//

HOPE MY ANSWER WOULD HELP YOU

REGARD MADHU@