What is #int sec^2(x)/(sqrt(1-tan^2x)) dx#? Calculus Introduction to Integration Integrals of Trigonometric Functions 1 Answer sjc Mar 22, 2018 #sin^(-1)(tanx)+c# Explanation: #I=int(sec^2x/(sqrt(1-tan^2x)))dx# us ethe substitution #u=tanx# #:. du=sec^2xdx# #=>I=int((sec^2x)/sqrt(1-u^2))xx (du)/sec^2x# #I=int (du)/sqrt(1-u^2)# this is a standard integral #I=sin^(-1)(u)+c# #=sin^(-1)(tanx)+c# Answer link Related questions How do I evaluate the indefinite integral #intsin^3(x)*cos^2(x)dx# ? How do I evaluate the indefinite integral #intsin^6(x)*cos^3(x)dx# ? How do I evaluate the indefinite integral #intcos^5(x)dx# ? How do I evaluate the indefinite integral #intsin^2(2t)dt# ? How do I evaluate the indefinite integral #int(1+cos(x))^2dx# ? How do I evaluate the indefinite integral #intsec^2(x)*tan(x)dx# ? How do I evaluate the indefinite integral #intcot^5(x)*sin^4(x)dx# ? How do I evaluate the indefinite integral #inttan^2(x)dx# ? How do I evaluate the indefinite integral #int(tan^2(x)+tan^4(x))^2dx# ? How do I evaluate the indefinite integral #intx*sin(x)*tan(x)dx# ? See all questions in Integrals of Trigonometric Functions Impact of this question 23192 views around the world You can reuse this answer Creative Commons License