How do you solve cosx=1/2cosx=12?

1 Answer
Sep 19, 2017

x=pi/3" or "x=(5pi)/3x=π3 or x=5π3

Explanation:

"since "cosx>0since cosx>0

"then x will be in the first/fourth quadrants"then x will be in the first/fourth quadrants

cosx=1/2cosx=12

rArrx=cos^-1(1/2)=pi/3larrcolor(blue)" angle in first quadrant"x=cos1(12)=π3 angle in first quadrant

"or "x=(2pi-pi/3)=(5pi)/3larrcolor(blue)" angle in fourth quadrant"or x=(2ππ3)=5π3 angle in fourth quadrant