View Full Version : Log and exponentials
dcfcviper
Nov 1, 2007, 06:07 AM
Hi,
I'm stuck with the following problem and need some help.
3(e^6x - 8e^3x) = -9
I've tried it two way and got the same wrong answer so any pointers towards the right one will be much appreciated :)
ebaines
Nov 1, 2007, 06:19 AM
Notice that e^6x is equal to (e^3x)^2. So you can express the problem as a quadratic equation, and use the quadratic formula to solve for e^3x. Does this help?
dcfcviper
Nov 1, 2007, 06:23 AM
No, I already tried that. Maybe my I made an error in the calculation then.
ebaines
Nov 1, 2007, 06:36 AM
No, I already tried that. Maybe my I made an error in the calculation then.
Try it again - it worked for me! What answer are you getting?
dcfcviper
Nov 1, 2007, 06:39 AM
Tried it again and got it now, thanks a lot :thup:
Must have missed something when doing it last night, had already done a fair bit of maths when trying to do this so was probably tired.
Thanks again.