The Graphs Of $y_{1}=0.25 x^{4}$ And $y_{2}=0.25\left(x^{4}+x^{3}-23 x^{2}+3 x+90\right)$ Are Shown in the Figure Below as Viewed on the Shown

Short Answer

The graphs of $y_{1}=0.25 x^{4}$ and $y_{2}=0.25\left(x^{4}+x^{3}-23 x^{2}+3 x+90\right)$ are shown in the figure below as viewed on the window $[-10,10]$ by $[-25,25]$ . What is the double zero of $y_{2}$ ?