How do you find all real numbers on the interval [0,2pi) that satisfy the equation and use radian measure 2sin^2(x)-3sin(x)=-1?

1 Answer
Mar 24, 2016

pi/6, pi/2, (5pi)/6

Explanation:

f(x) = 2sin^2 x - 3sin x + 1 = 0.
Solve this quadratic equation for sin x.
Since a + b + c = 0, use shortcut. The 2 real roots are:
sin x = 1 and sin x = c/a = 1/2.
a. sin x = 1 --> x = pi/2
b. sin x = 1/2. The trig unit circle gives 2 arcs that have the same sin value (1/2)
x = pi/6 and x = pi - pi/6 = (5pi)/6