trig
posted by Anonymous on .
evaluate the expression under the given conditions
tan 2 theta; cos theta=7/25, theta in quadrant I

If cosθ = 7/25 in QI, then sinθ = 24/25
That means tanθ = 24/7, and you (ahem) know that
tan2θ = 2tanθ/(1tan^2 θ)