Question

Find the exact value of $\cos 180°-\sin 180°$.

Answer 1

Compute the exact value:

We know that

$\cos 180°=-1$ and $\sin 180°=0$

Therefore,

$\cos 180°-\sin 180°=-1-0$

$=-1$

Hence, the exact value of $\cos 180°-\sin 180°$ is $-1$.