Yahoo Answers is shutting down on May 4th, 2021 (Eastern Time) and beginning April 20th, 2021 (Eastern Time) the Yahoo Answers website will be in read-only mode. There will be no changes to other Yahoo properties or services, or your Yahoo account. You can find more information about the Yahoo Answers shutdown and how to download your data on this help page.
Trending News
logarithm question, PLEASE HELP, i'd appreciate it!?
Solve the equation ex − e−x = 2.
5 Answers
- 9 years agoFavorite Answer
ex - e-x = 2
ex - 1/ex = 2
lcm
e2x - 1 = 2ex
e2x - 2ex -1 =0
put ex =t
t^2 -2t - 1 = 0
t = {-(-2) +- √(-2^2 - 4(1)(-1))}/2(1)
t = {2 +- √ (4+4)}/2
t = 1+- √2
so
ex= 1 + √2 and ex = 1-√2
so x = ln (1+√2)
and
x = ln (1-√2) (neglect this as ln argument cant be negative )
so answer is x = ln(1+√2)
x = ln(1+1.414)
= ln(2.414)
= 0.88137
- gerholdLv 44 years ago
(assets :-- log a N =z so N=a^z) log9 27=x 27=9^x (making use of the above assets) 3^3=3^2x by using fact the backside are comparable i.e=3 so equating the powers 3=2x x=3/2 log2 8=y 8=2^y (lower back making use of the valuables) 2^3=2^y lower back base is comparable i.e 2 so equating the powers y=3 log9 27 . log2 8=x*y=3/2*3=9/2
- Ed ILv 79 years ago
ex = 2 + e + x
x = (2 + e + x)/e
Maybe you meant: e^x - e^(-x) = 2.
e^(2x) - 1 = 2e^x
e^2x - 2e^x - 1 = 0
Let u = e^x
u^2 - 2u - 1 = 0
u^2 - 2u = 1
u^2 - 2u + 1 = 1 + 1
(e^u - 1)^2 = 2
e^u - 1 = ± √2
e^u = 1 ± √2
u = ln (1 + √2), because u - √2 < 0 and isn't in the domain of ln.
u = 1 + √2 = e^x
x = ln (1 + √2)
- How do you think about the answers? You can sign in to vote the answer.