Question #0d230

1 Answer
Aug 5, 2017

Depending on interval of integration, I get #+-1/(2(1-cosx)^2) +C#

Explanation:

#int (-sqrt(1+cosx))/(1-cosx)^(5/2) dx = int (-sqrt(1+cosx)(sqrt(1-cosx)))/((1-cosx)^(5/2)(1-cosx)^(1/2)) dx#

# = int(-sqrt(1-cos^2x))/(1-cosx)^3 dx#

# = int(-sqrt(sin^2x))/(1-cosx)^3 dx#

# = int(+-sinx)/(1-cosx)^3 dx#

Now integrate by substitution #u = 1-cosx# to get

# = +-1/(2(1 - cosx)^2) +C#

Note

The integrand is never positive, so the integral should be non-positive on any interval on which it exists as well.

So the indefinite integral should be:

#(-1)/(2(1 - cosx)^2) +C# #" "# (I think.)