If the value of the polynomial $x^{3} + 2 x^{2} - a x + 1$ at $x = 2$ is 11, then find the value of a.

a = 5

No worries! We‘ve got your back. Try BYJU‘S free classes today!

a = 3

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

a = - 2

No worries! We‘ve got your back. Try BYJU‘S free classes today!

a = - 9

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Open in App

Solution

The correct option is C $a = 3$
Let,
$p (x) = x^{3} + 2 x^{2} - a x + 1$
Given
$p (2) = 11$
$=> 2^{3} + 2 (2)^{2} - a (2) + 1 = 11$
$=> 8 + 8 - 2 a + 1 = 11$
$=> - 2 a = 11 - 8 - 8 - 1$
$=> - 2 a = - 6$
$=> a = \frac{6}{2}$
$=> a = 3$

Suggest Corrections

Similar questions

x^{3} + a x^{2} + 5

x^{3} - 2 x^{2} + a

(x + 2)

a

If 1 is a zero of the polynomial $a x^{2} - 3 (a - 1) x - 1$ then find the value of a.

x = \frac{1}{2 - \sqrt{3}}

x^{3} + 2 x^{2} - 7 x + 5

If $x = \frac{1}{(2 - \sqrt{3}),}$ then find the value of $(x^{3} - 2 x^{2} - 7 x + 5)$ .

(x - 2)

x^{3} + {2 x}^{2} - k x + 10

k

Join BYJU'S Learning Program