Question

If one zero of quadratic polynomial x²+3x+k is 2, then find the value of k

Answer 1

Given : Quadratic polynomial x^2+3x+k

One of the root is 2.

To find : The value of k

Solution :

Let the given quadratic polynomial be f(x)=x^2+3x+k

Given one of the zero of the quadratic polynomial is 2.

Hence f(2) = 0

Put x = 2 in f(x), we get

f(2)=2^2+3(2)+k

0=4+6+k

0=10+k

k=-10

Therefore

, The value of k is -10.