This may sound stupid but my mind has gone blank on how i would input logs into this equation.
3^x+1 = 15
Note: ^ means the 3 is to the power of x+1
I can use logs with e easy enough but stuck on this.
Throughout explanation would be grateful
2007-11-19 09:52:03 · 4 answers · asked by Paul T 1 in Science & Mathematics ➔ Mathematics
3^(x + 1) = 15
(x + 1) log 3 = log 15
(x + 1) = log 15 / log 3
x + 1 = 2.46
x = 1.46
Note
May use log to ANY base to calculate
log15 and log 3
2007-11-23 09:46:50 · answer #1 · answered by Como 7 · 0⤊ 0⤋
log(3^(x+1)) = log(15)
(x+1)log3 = log(15)
(x+1) = log(15)/log(3)
x = log(15)/log(3) - 1
=1.46
2007-11-19 17:56:19 · answer #2 · answered by norman 7 · 0⤊ 0⤋
Use the definition of logs to change it:
log(base3)(15) = x+1
that's it!
2007-11-19 17:55:46 · answer #3 · answered by Marley K 7 · 0⤊ 0⤋
3^(x+1)=15
(x+1)*ln3 = ln(15)
x = [ln(15)/ln(3)] - 1
=1.46497352 (approx)
2007-11-19 17:57:05 · answer #4 · answered by de4th 4 · 0⤊ 0⤋