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12-85.
  1. Rewrite each of the following expressions in a simpler form. Homework Help ✎

    1. cos2(θ – π) + sin2(θ – π)

    2. cos2(2w) – sin2(2w)

Review your work from problem 12-73 or the formulas in the Math Notes box in Lesson 12.2.3.

Remember:
cos²(θ) + sin²(θ) = 1.
The variable here is different, but will this change the identity? If you aren't sure, let U = θ − π

1

Remember:
cos²(x) − sin²(x) = cos(2x).

Try writing sin(θ) as opposite over hypotenuse and cos(θ) as adjacent over hypotenuse.
Simplify the complex fraction. Is the new ratio equivalent to another trig ratio?

tan(θ)