i need help with these problems

i really dont understand how to do them

1.

[2sin (x)]/[1-cos^2(x)]

i really appreciate your help

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- Aug 6th 2009, 06:25 PMdannyp32Simplifying trig expressions (help please)
i need help with these problems

i really dont understand how to do them

1.

[2sin (x)]/[1-cos^2(x)]

i really appreciate your help - Aug 6th 2009, 07:06 PMartvandalay11
$\displaystyle sin^2(x)+cos^2(x)=1$ is a well known identity (one that must be memorized)

So subtract $\displaystyle cos^2(x)$ from both sides to get $\displaystyle sin^2(x)=1-cos^2(x)$ so....

$\displaystyle \frac{2sin(x)}{1-cos^2(x)}=\frac{2sin(x)}{sin^2(x)}=\frac{2}{sin(x) }=2\csc(x)$