Question

Evaluate each expression under the given conditions.
tan(2x); cos(x) = 3/5
x, in Quadrant 1

Answer 1

use "double angle" formula for tangent.

Answer 2

\[\tan(2\theta)=\frac{2\tan(\theta)}{1-\tan^2(\theta)}\]
and you know that since
\[\cos(\theta)=\frac{3}{5}\] then \[\tan(\theta)=\frac{4}{3}\]

Answer 3

replace
\[\tan(\theta)\] in the formula by
\[\frac{4}{3}\] to get your answer