Find ∫sec3xdx.Answer: 21secxtanx+21log∣secx+tanx∣+CSolutionWrite sec3x=secx⋅sec2x and integrate by parts with u=secx, dv=sec2xdx:I=secxtanx−∫secxtan2xdx=secxtanx−∫secx(sec2x−1)dx.So I=secxtanx−I+∫secxdx, giving2I=secxtanx+log∣secx+tanx∣.21secxtanx+21log∣secx+tanx∣+CCBSE Class 12 Board · 2020 · Subjective