Question

4sin^2x + 4 sin x = 1

Answer 1

call sin x = x. Solve the quadratic equation 4x^2 + 4x - 1 = 0 by the quadratic formula. Get 2 real roots x1 = 0.21, and x2 rejected because < -1.
Use both calculator and trig unit circle to solve the basic trig equation
x = sin x = 0.21 to get the answers of arcs x (angle x) in degrees.