Let $f(x) =x^2-\ln x$ and $g(x)=2^x-x^2$. The graphs of $y=f(x)$ and $y=g(x)$ are shown below. The point $(a,b)$ is on the graph of functions $f$ and $g$.  **The value $x=a$ is a solution to which of the following equations?** [[☃ radio 1]]