Question

Use an appropriate half-angle formula to find the exact value of the expression.

tan(22.5degrees)

Answer 1

ugh... cant you use addition or subtraction instead?

Answer 2

I think the one for tan is:

sqrt(1-cos^2(x/2))
----------------
sqrt(1+cos^2(x/2))

Answer 3

x = 45

Answer 4

cos(2x) = 2cos^2(x) - 1

1+ cos(2x) = 2cos^2(x)....you the + is on the bottom ;)

Answer 5

sqrt(1-cos^2(x))
-------------- maybe better....
sqrt(1+cos^2(x))

Answer 6

yeah