Trigonometric functions: (also called circular functions, angle functions) are real functions which relate an angle of a right-angled triangle to ratios of two side lengths.
sinθ = cos(π2 - θ) = 1cscθ
cosθ = sin(π2 - θ) = 1secθ
tanθ = sinθ cosθ = cot(π2 - θ) = 1cotθ
cotθ = cosθ sinθ = tan(π2 - θ) = 1tanθ
secθ = csc(π2 - θ) = 1cosθ
cscθ = sec(π2 - θ) = 1sinθ
Find the x value of the equation：sin(x)-cos(x)=0