Find the value of cos 2 theta if theta is in the first quadrant and tan theta =15/4

Step-by-step explanation:

Given that:

Also, is in first quadrant.

To find:

Solution:

Let us have a look at the cosine of twice the angle in terms of tangent of the angle.

Suppose, we are given the value of , then the formula can be written as:

In terms of , we can re-write the formula as:

is in first quadrant, but can be in the second quadrant therefore, we have a negative value of our answer i.e. .

Therefore, the answer is:

the answer is 15% decrease

a) justify

step-by-step explanation:

justifying is just part of everyday life. justify kind of means proof so i think the answer is a) justify.