- #1

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## Homework Statement

This is only a step in a bigger example problem on trig substitution

2/3 *x

^{2}= sin

^{2}[tex]\theta[/tex]

[tex]\sqrt{}2/3[/tex] * x =sin[tex]\theta[/tex]

[tex]\theta[/tex] = arcsin([tex]\sqrt{}2/3[/tex] * x)

and

x = [tex]\sqrt{}3/2[/tex] * sin[tex]\theta[/tex]

This makes sense

Then I saw

dx / d[tex]\theta[/tex] = [tex]\sqrt{}3/2[/tex] * cos[tex]\theta[/tex]

Uh... why?

## Homework Equations

Regular trig equations

## The Attempt at a Solution

I have no idea