Guys thank you very much. I am sorry that I substituted 2tanx and forgot to type the 2. But now I finally found the answer by separate 1/cos^3x into (1/cosx)(tanx)' and work it out using integration by part.
Thank you
Homework Statement
I am told to find out the length of he curve y=¼x^2
Homework Equations
The length of the curve should be
∫√(1+¼x^2)dxThe Attempt at a Solution
I substituted tanx and got ∫2/cos^3x dx
So how could I continue and work out the solution? Should I use integration by part, or I...