# Variable-only graphing question

1. Sep 13, 2009

### Emethyst

1. The problem statement, all variables and given/known data
If F=Kx^n, where K>0 and n>1, sketch the graphs of F vs. x, F vs. x^n, and logF vs. logx. What information is obtained from each graph? Be specific.

2. Relevant equations
n/a

3. The attempt at a solution
No idea where to start with this one, as it's stumping me greatly. From the information given, i'm guessing that for the first graph of F vs. x it will be a simple linear graph, F vs. x^n will be a vertical parabola, and logF vs. logx will be a horizontal parabola, however, i'm unsure what information these graphs would give me (if they are even the right graphs I need to draw). If someone could point me in the right direction here it would be greatly appreciated, thanks in advance.

2. Sep 14, 2009

### HallsofIvy

Staff Emeritus
Why would you guess "that for the first graph of F vs. x it will be a simple linear graph"? What you normally see are graphs of "F vs. x". What does the graph of F= 2x^2 look. Now suppose you replace x^2 by u to get F= 2u. What would a graph of F= 2u look like? Finally, there is no need to guess about the third question, go ahead and take the logarithms. log(F)= log(kx^n)= ? Use the laws of logarithms.

3. Sep 14, 2009

### Emethyst

Ahh I think I see now. I'm guessing by the laws of logarithms you mean simplify log(kx^n) to logk + nlogx?