# roots

• Sep 18th 2011, 10:58 AM
planetdomi
roots
How is the following possible.
I realise I may be being very thick about this but I cant see it

4/√2 = 2x2/√2 = 2x√2 x √2/√2 = 2√2

What am I missing
• Sep 18th 2011, 11:06 AM
e^(i*pi)
Re: roots
Quote:

Originally Posted by planetdomi
How is the following possible.
I realise I may be being very thick about this but I cant see it

4/√2 = 2x2/√2 = 2x√2 x √2/√2 = 2√2

What am I missing

You're multiplying your equation by $\dfrac{\sqrt2}{\sqrt2} = 1$ so nothing is changing
• Sep 18th 2011, 11:09 AM
skeeter
Re: roots
Quote:

Originally Posted by planetdomi
How is the following possible.
I realise I may be being very thick about this but I cant see it

4/√2 = 2x2/√2 = 2x√2 x √2/√2 = 2√2

What am I missing

look at it from this point of view ...

$\frac{4}{\sqrt{2}} \cdot \frac{\sqrt{2}}{\sqrt{2}} = \frac{4 \cdot \sqrt{2}}{\sqrt{2} \cdot \sqrt{2}} = \frac{4\sqrt{2}}{2} = \frac{2 \cdot 2\sqrt{2}}{2} = 2\sqrt{2}$
• Sep 18th 2011, 11:13 AM
planetdomi
Re: roots
Thankyou so much