radicals

[tbth643]

I have an appendix to do for an online algebra 2 class. The first question is throwing me off for some reason. The appendix says:
1. Many people know that the weight of an object varies on different planets, but did you know that the weight of an object on Earth also varies according to the elevation of the object? In particular, the weight of an object follows this equation:W=Cr^-2 , where C is a constant, and r is the distance that the object is from the center of Earth.

a. Solve the equation W=Cr^-2 for r.
My first thought was to isolate the r term and convert the negative exponent, so to convert r^-2 you get 1/r^2 (I think) and then to isolate you divide by C on both sides leaving the equation W/C=1/r^2
Really, I am so lost with the many different rules and concepts that I do not know if this is right, and if it is right, what do I do next? This problem is important for me to solve the rest of the appendix (which I think I know how to solve the rest :? )

 

[Denis]

Solve the equation W=Cr^-2 for r.
My first thought was to isolate the r term and convert the negative exponent, so to convert r^-2 you get 1/r^2 (I think) and then to isolate you divide by C on both sides leaving the equation W/C=1/r^2

Correct; and W/C=1/r^2 becomes Wr^2 = C : r^2 = C/W ; r = sqrt(C/W).

 

[tbth643]

Thank you. This is an incredible site, I will be back

 

[mmm4444bot]

W = Cr^-2

Please type grouping symbols around exponents containing a negation sign.

You don't need to write it on paper this way, but it's good form when typing mathematical expressions.

Cheers

W = C r^(-2)