If 4 is a root of quadratic equation x2 + ax — 8 = 0, then a =

Q23 of 83 Page 90

If 4 is a root of quadratic equation x² + ax — 8 = 0, then a =

∵ 4 is a root –

⇒ 4² + a(4) – 8 = 0

⇒ 16 + 4a – 8 = 0

⇒ a = – 2

(A) doesn’t match the solution.

(B) doesn’t match the solution.

(D) doesn’t match the solution.

A quadratic equation has two equal roots, if…….

The quadratic equation has 3 as one of its roots.

If one of the roots of kx² — 7x + 3 = 0 is 3, then k =

The discriminate of x² — 3x — k = 0 is 1. A value of x is

Questions · 83

4. Quadratic Equations

1 1 1 1 1 1 1 2 2 2 2 3 3 3 3 4 4 4 4 4 4 1 1 1 1 1 1 2 3 3 4 5 5 5 5 5 5 1 2 3 4 5 6 7 8 1 1 1 1 1 2 2 2 2 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 23 23 23 23 23 23 23