Line integral of sin cos function

[jbowers9]

Homework Statement

integral (sin^4(x) + cos^4(x))^.5 dx

Homework Equations

sin^2(x) = (1 - cos^2(x))

The Attempt at a Solution

cos^4(x) + {1 - cos^2(x)}^2 = 2cos^4(x) -2cos^2(x) + 1
subst u = cos^2(x)
integral (2u^2 - 2u +1)^.5

 

[tiny-tim]

hi jbowers9!

(have a square-root: √ and try using the X² icon just above the Reply box )

cos^4(x) + {1 - cos^2(x)}^2 = 2cos^4(x) -2cos^2(x) + 1
subst u = cos^2(x)
integral (2u^2 - 2u +1)^.5

no, you've missed out the dx, which you need to write in the form f(u)du

(you could try using (cos²x + sin²x)², but i don't see how to finish that )