Question

1. f(x) = x2 + (k + 3) x + k
Find the discriminant of f(x) in terms of k.
A) k +3
B) 4k
C) k2+10 k+9
D) k2+2 k+ 9

Answer 1

Answer:

The correct answer is option D

Step-by-step explanation:

Concept:

Discriminant of of quadratic polynomial $ax^2+bx+c$ is $b^2-4ac$

Therefore discriminant of $f(x)=x^2+(k+3)x+k$ is

                            $=(k+3)^2-4k\\=k^2+6k+9-4k\\=k^2+2k+9$