30°
45°
60°
90°
Correct answer is C
2\sin^{2}\theta = 1 + \cos \theta \implies 2(1 - \cos^{2}\theta) = 1 + \cos \theta
2 - 2\cos^{2}\theta = 1 + \cos \theta
2 - 2\cos^{2}\theta - 1 - \cos \theta = 0
2\cos^{2}\theta + \cos \theta - 1 = 0
2\cos^{2}\theta + 2\cos\theta - \cos \theta - 1 = 0 \implies 2\cos \theta(\cos \theta + 1) - 1(\cos \theta + 1) = 0
(2\cos \theta - 1)(\cos \theta + 1) = 0 \implies \cos \theta = \frac{1}{2}
\theta = \cos^{-1} \frac{1}{2} = 60°
Given that P = {x : 1 \geq x \geq 6} and Q = {x : 2 < x < 10}. Where x are intege...
A body of mass 15kg is placed on a smooth plane which is inclined at&n...
A particle moving with a velocity of 5m/s accelerates at 2m/s^2. Find the distance it cover...
If y = 2(2x + \sqrt{x})^{2}, find \frac{\mathrm d y}{\mathrm d x}....
A body is acted upon by forces F_{1} = (10 N, 090°) and F_{2} = (6 N, 180°). Find th...
The sales of five salesgirls on a certain day are as follows; GH¢ 26.00, GH¢ 39....