Question

Evaluate the following :
$\frac{sin21}{cos69}$

Answer 1

We have $\sin (90-\theta )=\cos \theta$

therefore,

$\sin 21=\sin (90-69)=\cos 69$

To evaluate,

$\frac{\sin 21}{\cos 69}$

$=\frac{\cos 69}{\cos 69}$

$=1$