Find roots of polynomial $$ p(x) = 10x^3+20x-10x+15 $$
Answer
The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= -0.8612\\[1 em]x_2 &= 0.4306+1.2475i\\[1 em]x_3 &= 0.4306-1.2475i \end{aligned} $$Explanation
Step 1:
Combine like terms:
$$ 10x^3+ \color{blue}{20x} \color{blue}{-10x} +15 = 10x^3+ \color{blue}{10x} +15 $$Step 2:
Polynomial $ 10x^3+10x+15 $ has no rational roots that can be found using Rational Root Test, so the roots were found using qubic formulas.
This page was created using
Polynomial Roots Calculator