Answer:
{-π/2, π/2}
Step-by-step explanation:
Rewrite this as:
7sin^2 x - 14sin x + 7 = 0. Reduce this result by dividing all terms by 7:
sin^2 x - 2sin x + 1
Temporarily replace "sin x" with y:
y^2 - 2y + 1 = 0
Solve this through factoring: (y - 1)^2 = 0, or y - 1 = ± 0, or y = ±1
Recalling that y = sin x, we write
sin x = ±1, whose solutions are sin x = 1 and sin x = -1
The solution of sin x = 1 is π/2 and that of sin x = -1 is -π/2
and so the solution set is {-π/2, π/2}
