# Thread: the transformation that gives a straight line graph

1. ## the transformation that gives a straight line graph

Can you clarify this question for me:

Consider the relation y=25e^3x ,the transformation that gives a straight line graph is:

1)lny is plotted against ln(3x)
2)lny is plotted against lnx
3)y is plotted against x
4)y is plotted against lnx
5)lny is plotted against x

2. Originally Posted by change_for_better
Can you clarify this question for me:

Consider the relation y=25e^3x ,the transformation that gives a straight line graph is:

1)lny is plotted against ln(3x)
2)lny is plotted against lnx
3)y is plotted against x
4)y is plotted against lnx
5)lny is plotted against x
If $\displaystyle y = 25 e^{3x}$ then $\displaystyle \ln y = \ln 25 + \ln e^{3x} = \ln 25 + 3x$ so here it's $\displaystyle \ln y \; \text{vs}\; x$

3. Originally Posted by danny arrigo
If $\displaystyle y = 25 e^{3x}$ then $\displaystyle \ln y = \ln 25 + \ln e^{3x} = \ln 25 + 3x$ so here it's $\displaystyle \ln y \; \text{vs}\; x$

Thank you very much