A4. The solution to the equation $2^{x+1}=x^{2}+1$ lies in the interval
(A) $[0,1)$
(B) $(-3,-1)$
(C) $[-1,0]$
(D) $(0,2)$
(E) $(-4,-3)$
A4. We draw approximate graphs of the functions $f(x)=x^{2}+1$ and $g(x)=2^{x+1}$. We see that they intersect on the interval $[-1,0]$.

![](https://cdn.mathpix.com/cropped/2024_06_07_c1f0ff7099009a973f5fg-14.jpg?height=488&width=414&top_left_y=333&top_left_x=318)