integration

[roxstar1]

could someone please help me with this integral?
Im not sure if this is right, but here is my work so far...

integral [(sec3x)^3] dx

int. [(sec3x)(sec3x)^2]dx

int. [(sec3x)((tan3x)^2 +1)] dx

int. [sec3x (tan3x)^2]dx + int [sec 3x]dx


? + ln l sec3x + tan3x] dx + C

 

[royhaas]

Begin with an integration by parts and use an identity with the secant to replace the tangent function in the second integral from integration by parts.