Question

Find the cosine of ∠G (Must give explanation)

also why does my calculator say its undefined if I do the cos invert of (85/77) ??

cos^-1(85/77) = undefined ?? why

Answer 1

`\displaystyle \cos (G)=(36)/(85)`

Explanation:

Recall that cosine is the ratio of the adjacent side to the hypotenuse:

`\displaystyle \cos(G)=\frac{\text{adjacent}}{\text{hypotenuse}}`

The hypotenuse is always the side opposite to the right angle. In this case, it is

85.

The adjacent side to G is 36.

Therefore:

`\displaystyle \cos (G)=(36)/(85)`

For your other question, remember that in a right triangle, cosine is the ratio of the adjacent side to the hypotenuse.

As you know, the hypotenuse is always the longest side in a right triangle.

Therefore, the ratio of the adjacent side to the hypotenuse will never be greater than 1.

Since 85/77 is greater than 1, it is undefined.

The same applies to sine as well.