# Thread: Calculating midpoint of a line on logarithmic graph?

1. ## Calculating midpoint of a line on logarithmic graph?

I have to calculate the midpoint of a line drawn on a logarithmic graph, where the y axis is logarithmic, but the x axis is not. The two points are (1,5) and (8, 34). The midpoint of a line on a non-logarithmic graph is a different point that the midpoint of a logarithmic graph. At the moment, I'm checking my answers using a ruler to find the midpoint between the two points on the logarithmic graph. Can someone explain the solution in easy terms?

2. Originally Posted by picker pocker
I have to calculate the midpoint of a line drawn on a logarithmic graph, where the y axis is logarithmic, but the x axis is not. The two points are (1,5) and (8, 34). The midpoint of a line on a non-logarithmic graph is a different point that the midpoint of a logarithmic graph. At the moment, I'm checking my answers using a ruler to find the midpoint between the two points on the logarithmic graph. Can someone explain the solution in easy terms?
So the point is actually (x, ln(y))? Then (1, 5) corresponds, in a 'regular' graph, to $(1, e^5)$ and (8, 34) corresponds to $(8, e^{34})$. Find the midpoint of that as $(x, y_m)$ and then convert that to $(x, ln(y_m))$.