Solve the following equations :

Ideas required to solve the problem:

The general solution of any trigonometric equation is given as –

• sin x = sin y, implies x = nπ + (– 1)ⁿy, where n ∈ Z.

• cos x = cos y, implies x = 2nπ ± y, where n ∈ Z.

• tan x = tan y, implies x = nπ + y, where n ∈ Z.

given,

In all such problems we try to reduce the equation in an equation involving single trigonometric expression.

∴

⇒ { ∵ }

⇒ { ∵ cos A cos B + sin A sin B = cos (A - B)}

⇒

If cos x = cos y, implies x = 2nπ ± y, where n ∈ Z

∴

∴