SOLUTION: Graph y1=6^3x+1 and y2=215 find the point of intersection. I know y = 215 but how do I find X? Solve this as a logarithm.

Algebra ->  Exponential-and-logarithmic-functions -> SOLUTION: Graph y1=6^3x+1 and y2=215 find the point of intersection. I know y = 215 but how do I find X? Solve this as a logarithm.      Log On


   

Question 945924: Graph y1=6^3x+1 and y2=215 find the point of intersection. I know y = 215 but how do I find X? Solve this as a logarithm.
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
Graph y1=6^3x+1 and y2=215 find the point of intersection. I know y = 215
:
a graphing table to plot this:
x | y
-------
0 | 2
.2 | 3.9
.4 | 9.6
.6 | 26
.8 | 74.7
1.0| 217, exceeds 215
looks like this
+graph%28+300%2C+200%2C+-1%2C+2%2C+-100%2C+300%2C+6%5E%283x%29%2B1%2C+215%29
:
find out what x is when y = 215
6%5E%283x%29%2B1+=+215
Subtract 1 from both sides
6%5E%283x%29+=+214
log%28%286%5E%283x%29%29%29+=+log%28%28214%29%29
log equiv of exponents
3x%2Alog%28%286%29%29+=+log%28%28214%29%29
3x = log%28%28214%29%29%2Flog%28%286%29%29
using the calc
3x = 2.9948
x = 2.9948%2F3
x = .99827, almost 1, agrees with the graph