## College Algebra (10th Edition)

$\displaystyle \{\frac{\ln\pi}{1+\ln\pi}\}$ or $\{0.534\}$
... Apply $\ln$(...) to both sides and isolate x $\ln\pi^{1-x}=\ln e^{x}$ $(1-x)\ln\pi=x$ $\ln\pi-x\ln\pi=x$ $\ln\pi=x+x\ln\pi$ $\ln\pi=x(1+\ln\pi)$ $x=\displaystyle \frac{\ln\pi}{1+\ln\pi}\approx 0.534$ The solution set is $\displaystyle \{\frac{\ln\pi}{1+\ln\pi}\}$ or $\{0.534\}$