Question

不定积分两道计算∫(X^3)根号(1-x^2)dx ∫(X^3)根号(1+x^2)dx

Answer 1

∫(sin^2x+cos^2x)/(sin^2xcos^2x)dx

=∫1/(sin^2x+2cos^2x)dx

=∫1/(cos^2x)dx