Trig Substitution

Trig Substitution

A method for computing integrals often used when the integrand contains expressions of the form a² – x², a² + x², or x² – a².

Table showing trig substitutions: a²–x² use x=a sinθ; a²+x² use x=a tanθ; x²–a² use x=a secθ
Right triangle with hypotenuse 2, vertical side x, horizontal side √(4−x²), where x/2 = sinθ, illustrating trig substitution.

See also

u-substitution