Question

Evaluate :$\cos 48°–\sin 42°$

Answer 1

To evaluate :$\cos 48°–\sin 42°$

We know that, $48°={90}^0-{42}^0$

⇒ $\cos {48}^0=\cos ({90}^0-{42}^0)$

⇒ $\cos {48}^0=\sin {42}^0$

Now $\cos 48°–\sin 42°$$=\sin {42}^0-\sin {42}^0$

$=0$

Thus, $\cos 48°–\sin 42°$$=0$.