how do I integrate (3)/(x^2 + 9) dx using partial fractions? Thank you.

Question

anonymous · Answer

you don't need partial fractions .. assume x = 3 tany .. then substitute .. you would get get 
1/3 taninv(x/3) as your answer...

anonymous · Answer

srry u wd get taninv(x/3) as answer..

anonymous · Answer

what happens to the 1/3?

anonymous · Answer

the coefficient?

anonymous · Answer

..And how can you know to assume a tan. function?

anonymous · Answer

you can assume the tan function because you change the coordinates. .. see integration is nothing but area under the curve .. when you integrate f(x) in x you find area under the curve for when f(x)is plotted in xy plane.. when i write x = tany I am calculating area for the same graph in a different plane .. value of my area would remain the same... I hope this helps

anonymous · Answer

Kind of, can you elaborate some more?

anonymous · Answer

check this website ... http://www.sosmath.com/calculus/integration/substitution/substitution.html