If x - 2 is a factor of x 3 - kx - 12, then the value of k is :

ICSE Class 10 Mathematics PYQ · 2023 Paper · Section A

1(ii)1 Mark · 2023 · Section A · 2023 Paper

If x - 2 is a factor of x3 - kx - 12, then the value of k is :

Show SolutionHide Solution↓

By factor theorem,

If x - a is a factor of f(x), then f(a) = 0.

Given,

x - 2 is a factor of x3 - kx - 12

⇒ x - 2 = 0

⇒ x = 2.

∴ 23 - 2k - 12 = 0

⇒ 8 - 2k - 12 = 0

⇒ -2k - 4 = 0

⇒ 2k = -4

⇒ k = $-\frac{4}{2}$ = -2.

Hence, Option 3 is the correct option.

← Previous questionNext question →

Browse the free Mathematics sample bank