Solving Algebraic Expressions with Potens Rules | Quick Homework Question

[christian0710]

Homework Statement

I stated this as a small attached photo, since i still need to learn to write in latex (see photo)

Homework Equations

How do you transform the first expression into the next expression (on photo)?

The Attempt at a Solution

[/B]I tried various manipulations with potens rules, but I'm really lost here, please help me out.,

 

[SteamKing]

I'm not sure what 'potens' rules are, but how do you bring anything under the radical sign? What must you do to it first?

Or as an alternate approach, if you add the expressions together under the radical on the RHS and simplify, what do you get?

 

[christian0710]

I'm not sure what 'potens' rules are, but how do you bring anything under the radical sign? What must you do to it first?

Or as an alternate approach, if you add the expressions together under the radical on the RHS and simplify, what do you get?

I'm unsure of that: what must you do to bring something under the radical sign? I'm suck with respect to that trick.

 

[christian0710]

Ohh wait now I get it, if you take the square root of dt^2 then both terms are under the radical :)

 

[PeroK]

I'm unsure of that: what must you do to bring something under the radical sign? I'm suck with respect to that trick.

I don't have any compehension of what the LHS means. But, in terms of "algebra", the identity is only true if dt is positive.

$\frac{\sqrt{a^2 + b^2}}{c} = \pm \sqrt{\frac{a^2}{c^2} + \frac{b^2}{c^2}}$