## cos^2x (Power to Double Angle)

### 1/2(1+cos2x)

To derive the formula for cos^2x in terms of double angle:

We know that cos2x = cos(x + x) = cosxcosx – sinxsinx

Also, sin^2x + cos^2x = 1

Rearranging the above equation, we get cos^2x = 1 – sin^2x

Substituting sin^2x = 1 – cos^2x in the formula for cos2x, we get:

cos2x = cosxcosx – (1 – cos^2x)

Simplifying the equation, we get:

cos2x = 2cos^2x – 1

Rearranging the above equation, we get:

cos^2x = (1 + cos2x) / 2

Therefore, the formula for cos^2x in terms of double angle is:

cos^2x = (1 + cos2x) / 2.

This formula can be used to simplify trigonometric expressions involving cos^2x.

##### More Answers:

The Absolute Value Function: Definition And Examples.Even Symmetry Of Cosine Function And Deriving Its Result For Cos(-X) = Cos(X)

Mastering The Double Angle Formula For Sin^2X: A Comprehensive Guide

Error 403 The request cannot be completed because you have exceeded your quota. : quotaExceeded