Question

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

Answer 1

Answer: k = - 10.

Explanation: Let, p(x) = x^2 + 3x + k. It is given that 2 is the zero of p(x).

∴ p(2) = 0

→ (2)^2 + 3(2) + k = 0

→ k = - 4 - 6

→ k = - 10.

More: Relationship between zeroes and coefficients or constant terms in an quadratic polynomial:- (ax^2 + bx + c.)

• $\sf \alpha + \beta = - \dfrac{Coefficient \ of \ x}{Coefficient \ of \ x^2}$
• $\sf \alpha \beta = \dfrac{Constant \ term}{Coefficient \ of \ x^2} .$