Share
Explore BrainMass

Double-angle and half-angle

Given tanx = 2 and the quadrant is 1.
Identify sin2x, cos2x, and tan2x using the double-angle and half-angle formulas.

Solution Preview

Double-Angle formula
Tan(2x)=2tan(x)/(1-tan(X)^2)=2*2/(1-2^2)= -4/3
Since angle X is in quadrant 1, we know that 2X is in quadrant 2 ...

Solution Summary

This shows how to use the double-angle and half-angle formulas.

$2.19