Question

Solve the inequality. Express the exact answer in interval notation, restricting your attention to -2π≤x≤2π. sin(2x)≥sin(x)

Answer 1

sin(2x)=2sin(x)cos(x)

2sin(x)cos(x)-sin(x)>=0
sin(x)[2cos(x)-1]>=0

Answer 2

Find when sin(x)[2cos(x)-1] is zero
Then draw a number line and test the intervals around the zeros to see if it is pos or neg