# Math Help - simple equation

1. ## simple equation

Im having difficulty understanding something simple:

Can someone show me how it is possible to get from

2a² = d²

to

d = a√2

many thanks

2. ## Re: simple equation

Originally Posted by planetdomi
Im having difficulty understanding something simple:

Can someone show me how it is possible to get from

2a² = d²

to

d = a√2

many thanks
Well first of all, that answer is wrong, but anyway...

\displaystyle \begin{align*} d^2 &= 2a^2 \\ \sqrt{d^2} &= \sqrt{2a^2} \\ |d| &= \sqrt{2}\sqrt{a^2} \\ |d| &= \sqrt{2}\,|a|\textrm{ or, if you like} \\ d &= \pm \sqrt{2}\,a \end{align*}

3. ## Re: simple equation

wow

Thankyou so much