Find all real numbers in the interval 0 2 pi that satisfy th
Find all real numbers in the interval [0, 2 pi) that satisfy the equation. Use radian measure. 7 sin^x - 2sinx = cos^2x The solution set is (Round to the nearest tenth as needed Use a comma to separate answers as needed)
Solution
7sin^2 x -2sin x=cos^2 x
7sin^2 x -2sin x= 1-sin^2x
8sin^2 x -2sin x -1=0
8sin^2 x -4sin x +2sin x-1=0
4sin x(2sin x -1)+1(2sin x-1)=0
(4sin x +1)(2sin x-1)=0
Sin x=-1/4 ,sin x=1/2
x= .253, 2.889 ,x= pi/6,5pi/6
