## richyw Group Title Having trouble with some algebra 2 years ago 2 years ago

1. lgbasallote

welcome to the club

2. richyw

my solutions manual goes from $\vec{E}=k_eq\left( \frac{1}{(x-a)^2}-\frac{1}{(x+a)^2}\right)\hat{i}$to$\vec{E}=k_eq\frac{4ax}{(x^2-a^2)^2}\hat{i}$ and I can't quite remember how to get that!

3. richyw

I can get to $\vec{E}=k_eq\left(\frac{4ax}{(x-a)^2(x+a)^2}\right)\hat{i}$ so basically I have forgotten how to deal with the denominator :O

4. richyw

without expanding it all out of course...

5. ganeshie8

$$\vec{E}=k_eq\left(\frac{4ax}{(x-a)^2(x+a)^2}\right)\hat{i}$$ $$\vec{E}=k_eq\left(\frac{4ax}{((x-a)(x+a))^2}\right)\hat{i}$$

6. richyw

oh wow

7. richyw

i need to sleep haha

8. ganeshie8

haha i agree ;p

9. richyw

thanks a lot

10. ganeshie8

np :)