Final answer:
The question asks to simplify a trigonometric expression using identities. By applying the Pythagorean trigonometric identity, sin^2x + cos^2x = 1, the expression simplifies to cos^2x.
Step-by-step explanation:
The student's question, 1-sin2x / sin2x + cos2x, involves simplifying a trigonometric expression. We know from the Pythagorean trigonometric identity that sin2x + cos2x = 1. Therefore, we can rewrite the expression by replacing the denominator with 1, resulting in:
1 - sin2x = cos2x
Now the expression simplifies to:
cos2x / 1 = cos2x
Thus, the simplified form of the original expression is cos2x. This uses the fundamental properties of trigonometric identities to simplify the expression.