# How do you evaluate P(-1/2) if P(x) = 2x^4 + x^3 + 12?

May 14, 2018

$P \left(- \frac{1}{2}\right) = 12$

#### Explanation:

$\text{to evaluate } P \left(- \frac{1}{2}\right)$

$\text{substitute "x=-1/2" into } P \left(x\right)$

$P \left(\textcolor{red}{- \frac{1}{2}}\right) = 2 {\left(\textcolor{red}{- \frac{1}{2}}\right)}^{4} + {\left(\textcolor{red}{- \frac{1}{2}}\right)}^{3} + 12$

$\textcolor{w h i t e}{\times \times \times} = \left(2 \times \frac{1}{16}\right) - \frac{1}{8} + 12$

$\textcolor{w h i t e}{\times \times \times} = \cancel{\frac{1}{8}} \cancel{- \frac{1}{8}} + 12 = 12$