1. The problem statement, all variables and given/known data cos(x)+2tg(x) = 7/(4*cosx(x)) Solve for x on the real numbers set. 2. Relevant equations tg(x) = sin(x)/cos(x) , cos^2(x) = 1-2*sin^2(x) , The determinant is D = b^2 - 4ac , Also cos(x) ,tg(x), sin(x) | -1 < x < 1 3. The attempt at a solution For final arrangement I got is: -8sin^2(x) + 8sin(x) - 3 = 0 But the determinant is 8^2 - 4*(-8)*(-3) which is 64 - 96 thus the equation doesn't have a real solution. I checked on WolframAlpha and it has some weird solutions and I was also told that it does have a real solution.