Thread: Double Angle Identities

Use an identity to write each expression as a trig function value or as a single number.

1-2sin^2(22 1/2 degrees)


and

1/4 - 1/2 sin^2 (47.1 degrees)

Thanks for reading!

Hello Thatoneguy12345

Originally Posted by Thatoneguy12345

Use an identity to write each expression as a trig function value or as a single number.

1-2sin^2(22 1/2 degrees)


and

1/4 - 1/2 sin^2 (47.1 degrees)

Thanks for reading!

These both use the identity

1)

2) , and you can't simplify this any further.

Grandad

wait for the first one, how did you get cos45?

I begin with 1 - 2 sin ^ 2 (22 1/2) and I end up multiplying the 22 with 1/2 and getting 11. So I end up with 1-2sin^2 11. Is that the correct step?

NVM I get it! Thanks a lot