Let u be the value of tan(x) and that the equation above may also be written as,
u² - 3u + 2 = 0
The equation can be factored as follows,
(u - 1)(u - 2) = 0
u - 1 = 0 ; u = 1 and u - 2 = 0 ; u = 2
Thus, tangent(x) = 1 and tangent(x) = 2. The values of x are 45° and 63.43°.