Question

Find the value of the polynomial

$2a^2-5a^3+7a-3$ at $a=0,2$ and $-1$.

• A. $p\left(0\right)=-3,p\left(2\right)=-21,p(-1)=-3$
• B. $p\left(0\right)=-2,p\left(2\right)=-1,p(-1)=-3$
• C. $p\left(0\right)=3,p\left(2\right)=-13,p(-1)=-3$
• D. $p\left(0\right)=2,p\left(2\right)=-16,p(-1)=-3$

Answer 1

The correct option is A $p\left(0\right)=-3,p\left(2\right)=-21,p(-1)=-3$

Let,
$p\left(a\right)=2a^2-5a^3+7a-3$
$p\left(o\right)=2(0{)}^2-5(0{)}^3+7\left(0\right)-3$
$=-3$
$p\left(2\right)=2(2{)}^2-5(2{)}^3+7\left(2\right)-3$
$=8-40+14-3$
$=-21$
$p(-1)=2(-1{)}^2-5(-1{)}^3+7(-1)-3$
$=2+5-7-3$
$=-3$