# rearranging equation

• Jul 7th 2008, 04:49 AM
scarface1
rearranging equation
Hi Im a bit confused with the following
how do I rearrange the equation below so I can calculate the value of d
• Jul 7th 2008, 04:55 AM
Simplicity
Quote:

Originally Posted by scarface1
Hi Im a bit confused with the following
how do I rearrange the equation below so I can calculate the value of d

All the values which are in the denominator are multiplied to bring it to other side and all values which are in the numerator are divided to bring it to the other side. Do this for all values except $d$.

$G = \sigma \frac{\pi d^2}{4D}$

Multiplying by $4D$ and divide by $\sigma \pi$ each side to obtain:

$\frac{4DG}{\pi \sigma} = d^2$

Square root both side to obtain $d$ on its own as a subject.

$d = \sqrt{\frac{4DG}{\pi \sigma}}$
• Jul 7th 2008, 11:53 PM
Isomorphism
Quote:

Originally Posted by Air
Square root both side to obtain $d$ on its own as a subject.

$d = \sqrt{\frac{4DG}{\pi \sigma}}$

Since we dont know the domain of d, just to be precise:

$d = \pm \sqrt{\frac{4DG}{\pi \sigma}}$
• Jul 8th 2008, 02:45 AM
scarface1
Hi guys

Thank you so much for your help. I understand it a lot better now!