Question
Find roots of polynomial $$ p(x) = r^2+4r $$
Answer
The roots of polynomial $ p(r) $ are:
$$ \begin{aligned}r_1 &= 0\\[1 em]r_2 &= -4 \end{aligned} $$Explanation
Step 1:
Factor out $ \color{blue}{ r }$ from $ r^2+4r $ and solve two separate equations:
$$ \begin{aligned} r^2+4r & = 0\\[1 em] \color{blue}{ r }\cdot ( r+4 ) & = 0 \\[1 em] \color{blue}{ r = 0} ~~ \text{or} ~~ r+4 & = 0 \end{aligned} $$One solution is $ \color{blue}{ r = 0 } $. Use second equation to find the remaining roots.
Step 2:
To find the second zero, solve equation $ r+4 = 0 $
$$ \begin{aligned} r+4 & = 0 \\[1 em] r & = -4 \end{aligned} $$This page was created using
Polynomial Roots Calculator