# Algerbra in Astrophysics

I am realy quite terrible at rearranging equations, I wonder if anyone could help?

How can I rearrange : m-M=5log10(d/10) to give d=?

Thanks for any imput.

## Answers and Replies

Cyosis
Homework Helper
First divide by 5, $(m-M)/5=\log_{10}(d/10)$. To get get rid of the log_10 you take 10^ on both sides.

$$10^{\frac{m-M}{5}}=\frac{d}{10}$$

Now multiply by 10.

Cheers! This helps alot!

what is this simple calculation has to do with "Astrophysics" ...???

what is this simple calculation has to do with "Astrophysics" ...???

This is the calculation for magnitudes. It's the bane of all new undergraduate astrophysics students :tongue:

Wallace
Science Advisor
Stupid backwards magnitudes! I've seen even seasoned astronomers get in a verbal tangle using the wrong adjective to describe some magnitude (i.e. 'as high as' instead of 'as low as' or vice versa). No wonder beginners have trouble...

Chronos
Science Advisor
Gold Member
Magnitude is a pretty obscure and confusing measure of brightness. Think 2 to the fifth power.