Solve For r

[mathdad]

Given R = (CL)/r^4, solve for r.

Solution:

Given R = (CL)/r^4.

Multiplying both sides by r^4, I got:

Rr^4 = CL

r^4 = CL/R

sqrt{r^4} = sqrt{CL/R}

r^2 = sqrt{CL/R}

sqrt{r^2} = sqrt{sqrt{CL/R}}

r = sqrt{sqrt{CL/R}}

Yes?

 

[MarkFL]

When you get to:

[MATH]r^4=\frac{CL}{R}[/MATH]
I would next write:

[MATH]r=\pm\sqrt[4]{\frac{CL}{R}}[/MATH]
or:

[MATH]r=\pm\left(\frac{CL}{R}\right)^{\frac{1}{4}}[/MATH]
This is assuming we are only after real solutions.

 

[mathdad]

When you get to:

[MATH]r^4=\frac{CL}{R}[/MATH]
I would next write:

[MATH]r=\pm\sqrt[4]{\frac{CL}{R}}[/MATH]
or:

[MATH]r=\pm\left(\frac{CL}{R}\right)^{\frac{1}{4}}[/MATH]
This is assuming we are only after real solutions.

Ok. Nicely done. I know where the power of 1/4 comes from.