Principle solution of trigonometric equation restrict the solution in the Range 0 <= x < 2π.
The expression involving integer ’n’ which gives all solutions of a trigonometric equation is called general solution
To derive the general solution , we use the periodicity of trigonometric functions .
Period of Sin(x) = 2π
Cos(x) = 2π
Tan(x)=π
For general solution , we also use some Standard results.
1) if Sin(x) = Sin (y) => x = nπ +(-1)^n * y , where n is an integer.
2) if Cos(x) = Cos(y) => x = 2nπ y + - y , where n is an integer.
3) if x & y are not multiple of π/2
Then Tan(x) = Tan(y) => x = nπ + y , where n is an integer .