How do you solve $x^x=x$

logarithms

I have tried to solve this by taking the natural log of both sides and got $x\ln(x)=\ln(x)$ and after I subtracted $\ln(x)$ from both sides I got $x\ln(x)-\ln(x)=0$ which using the distributive property becomes $(x-1)\ln(x)=0$ so either $x-1=0$ or $\ln(x)=0$ and in both cases $x=1.$ what I am confused about is that $(-1)^{-1}=(-1)$ and when I solved the equation I did not get this answer. Can somebody please tell me where I messed up and how to properly solve this equation?

Best Answer

When you take the natural logarithm of both sides you need to put the operand in an absolute value. Then your final equation would be $\ln|x|=0$ $\implies$ $x=1$ or $x=-1$.

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