Thread: Quotient and powers problem

Hello all,

I'm having one of those moments staring at some working in my textbook that I just can't get my head around. I'd rather have a poke in the right direction than a straight solution, but whatever is easier for you guys!

There are two steps in this working, I just cant see how to get from one to the next. I've tried writing it out in as many ways as I can think of, but I know I'm just missing that one tiny connection!

From this to this

In fact, ignore the 1/200. It's just the second quotient I'm struggling with...

If we say that x^2 + y^2 = a

Then we have a/sqrt(a)

anything divided by the square root of itself = the square root of itself,

so a/sqrt(a) = sqrt(a) = sqrt(x^2 + y^2)

Originally Posted by sirellwood

If we say that x^2 + y^2 = a

Then we have a/sqrt(a)

anything divided by the square root of itself = the square root of itself,

so a/sqrt(a) = sqrt(a) = sqrt(x^2 + y^2)

And why does this work? Because, if a is positive,



by virtue of cancellation.

Multiply both numerator and denominator by

Originally Posted by VincentP

Multiply both numerator and denominator by

That works, too.