If $$\ \frac{cos\theta}{1+sin\theta}+\frac{cos\theta}{1-sin\theta}\ $$= 4 and $$\ \theta\ $$is acute, then what is the value of (in degrees) of $$\ \theta$$?

Expression : $$\ \frac{cos\theta}{1+sin\theta}+\frac{cos\theta}{1-sin\theta}\ =4$$

=> $$cos\theta( \frac{1}{1+sin\theta}+\frac{1}{1-sin\theta}) =4$$

=> $$cos\theta(\frac{(1-sin\theta)+(1+sin\theta)}{(1+sin\theta)(1-sin\theta)})=4$$

=> $$cos\theta\times\frac{2}{1-sin^2\theta}=4$$

=> $$cos\theta\times\frac{1}{cos^2\theta}=\frac{4}{2}$$

=> $$\frac{1}{cos\theta}=2$$

=> $$cos\theta=\frac{1}{2}$$

=> $$\theta=cos^{-1}(\frac{1}{2})=60^\circ$$

=> Ans - (C)