# multiplying two fractions

• Dec 13th 2009, 08:52 PM
bgonzal8
multiplying two fractions
(1/acrtan(x)) * (1/1+x^2)

do I multiply each fraction by the opposite denominator to get a common denominator and then multiply the numerator together?

[(1+x^2)(acrtan(x))] / (arctan(x)*(1+x^2)

but they don't cancel out right?

does it equal [arctan(x) + x^2acrtan(x)] /arctan(x) (1+x^2) ????? It doesn't seem right at all.
• Dec 13th 2009, 09:01 PM
VonNemo19
Quote:

Originally Posted by bgonzal8
(1/acrtan(x)) * (1/1+x^2)

do I multiply each fraction by the opposite denominator to get a common denominator and then multiply the numerator together?

[(1+x^2)(acrtan(x))] / (arctan(x)*(1+x^2)

but they don't cancel out right?

does it equal [arctan(x) + x^2acrtan(x)]/arctan(x) (1+x^2) ????? It doesn't seem right at all.

$\displaystyle \frac{1}{\arctan{x}}\cdot\frac{1}{(1+x^2)}=\frac{1 }{(\arctan{x})(1+x^2)}=\frac{1}{\arctan{x}+x^2\arc tan{x}}$.

I'm not quite sure why you'd want to multiply out and actually make the expression less simple...