2 sin A cos Acos2 A − sin2 A

The expression you've given seems to be a trigonometric identity. However, it's not clear because the expression is not properly formatted.

If you meant to write "2 sin A cos A cos^2 A - sin^2 A", then we can simplify it as follows:

Step 1: Recognize that 2 sin A cos A is the double angle identity for sin 2A. So, the expression becomes:

sin 2A cos^2 A - sin^2 A

Step 2: Recognize that cos^2 A = 1 - sin^2 A (from the Pythagorean identity). Substitute this into the expression:

sin 2A (1 - sin^2 A) - sin^2 A

Step 3: Distribute sin 2A:

sin 2A - sin^2 A sin 2A - sin^2 A

This is the simplified form of the expression. If you meant a different expression, please provide the correct one.