Question

Find the value of the polynomial $5x-4x^2+3$ at
(i) $x=0$
(ii) $x=-1$
(iii) $x=2$

Answer 1

Let, $p\left(x\right)=5x-4x^2+3$

(i) At $x=0$,

$p\left(0\right)=5\left(0\right)-4(0{)}^2+3$

$=3$

$\therefore p\left(0\right)=3$

(ii) At $x=-1$,

$p(-1)=5(-1)-4(-1{)}^2+3$

$=-5-4+3$

$\therefore p(-1)=-6$

(iii) At $x=2$,

$p\left(2\right)=5\left(2\right)-4(2{)}^2+3$

$=10-16+3$

$\therefore p\left(2\right)=-3$