h(x) = 2ln((x-1)/2)+3 Range and domain this function What is the inverse of the function :)
any takers please
ln((x-1)/2)
if the input is \(\frac{x-1}{2}\) then solve \[\frac{x-1}{2}>0\] for \(x\)
the range of the log is all real numbers
so x must be greater than 1 and y is an element of all the reals?
yes
you want the inverse solve \[x=2\ln(\frac{y-1}{2})+3\] for \(y\) in a few steps
only one step is not algebra subtract 3 divide by 2 not algebra step, write in exponential form etc
I have got to \(-3/2 = ln(x-1/2)\)
??
i just get so confused with exponentials etc :(
k lets go slow
\[x=2\ln(\frac{y-1}{2})+3\] we solve for \(y\) using almost all algebra
thank you for your patience :)
a) subtract 3 get \[x-3=2\ln(\frac{y-1}{2})\]
b) divide by 2, get \[\frac{x-3}{2}=\ln(\frac{y-1}{2})\]
c) the only non algebra step write in equivalent exponential form , the base of the natural log is \(e\) so in exponential form this is \[\large e^{\frac{x-3}{2}}=\frac{y-1}{2}\]
d) back to algebra multiply by 2 get \[\large 2e^{\frac{x-3}{2}}=y-1\]
finally e) add 1 get \[\large 2e^{\frac{x-3}{2}}+1=y\] and that is your inverse
domain x is an element of all the reals and y must be greater than 1?
yes i would say that is right
Can you help me with one more and I will leave you alone LOL
since it is the reverse of the previous one with domain range switched
k
i(x) = 1-3x10^2x+3 Domain and range, plus inverse :)
i can't really read it
looks like \[1-3x10^{2x}+3\]
but maybe \[1-3\times 10^{2x+3}\]
\[i(x)=1-3\times10^{2x+3}\]
ok domain as usual is all real numbers range is \((-\infty,1)\) since \(10^x\) is never negative
so range must be less than 1?
yes
you want the inverse solve \[x=1-3\times 10^{2y+3}\] for \(y\) again almost all algebra
when you get to \[-\frac{x-1}{3}=10^{2y+3}\] this time write in equivalent logarithmic form
\[\log_{10} (-\frac{ y-1 }{ 3})=2x+3\]
sorry x and y back to front
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