Question

Cos31°cosl° + sin31°sinl°

Answer 1

Ответ:

=cos(31°-1°)=cos 30°=√3/2

Answer 2

The expression you provided is a trigonometric expression involving the cosine and sine of two angles, 31 degrees and $l$ degrees. Let's simplify this expression using trigonometric identities.

The trigonometric identity we'll use is the cosine of the difference of angles:

$\cos(a - b) = \cos a \cos b + \sin a \sin b$

In this case, $a = 31^\circ$ and $b = l^\circ$, so we can rewrite the given expression using this identity:

$\cos(31^\circ - l^\circ)$

So, the simplified expression is $\cos(31^\circ - l^\circ)$.