When you multiply 2cos(t) by 2cos(t), do you get 4cos(t)^2 or 4cos^2(t)? And also, assuming I have decided to make the defined integral ((4cos(t)^2 + 25 + 4sin(t)^2))^1/2, do I solve this one by substitution? Because I don't see how. Maybe by completing the square? This is going back to college Calculus but I can't remember what it is exactly I should do to integrate this expression.

Thanks for the help.