Question

Find the value of $P(-1)$ if the function $P$ is defined as follows:
for $x>0,P\left(x\right)=x^5+x^4-36x-36$
$x<0,P\left(x\right)=-x^5+x^4+36x-36$

• A. -70
• B. -36
• C. 0
• D. 36
• E. 70

Answer 1

The correct option is A -70

We know $x<0$, then $P\left(x\right)=-x^5+x^4+36x-36$

$\Rightarrow P(-1)=-(-1{)}^5+(-1{)}^4+36(-1)-36$

$\Rightarrow P(-1)=1+1-36-36$

$\Rightarrow P(-1)=2-72=-70$