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## Homework Statement

Integral of 6/(sqrt(4-x^2))

## Homework Equations

arcsin(u) = u'/ sqrt(1-u^2)

## The Attempt at a Solution

WA gave a different answer

http://www.wolframalpha.com/input/?i=Integral+of+6%2F%28sqrt%284-x^2%29%29

I got the following:

Integral of 6/(sqrt(4-x^2))

divide by 4 to reduce to 1-u^2, and pull out the constant 4: 1/4 int of 6/sqrt(1-(x/2)^2

i was going to pull out the six right away, but i could integrate that with du.

u = x/2, du = 1/2 dx, so 2 du = dx

i get 12 inside, and pull out the 12, i get 12/4 int u' / sqrt(1-u^2)

which gives me 3 arcsin(x/2)+c

but this is not right from WA.

Thank you.