Polynomials
CBSE 2026 Board Exam Set 1 (Code 30/7/1)
CBSE_BOARD_PYQ_2026_30_7_1
Grade 10
Question:
[Section A]
If the sum of the zeroes of the quadratic polynomial $k x^2 + 2x + 3k$ is equal to their product, then the value of $k$ is:
(A) $1/3$
(B) $-1/3$
(C) $2/3$
(D) $-2/3$
Step-by-Step Solution
Key Concept: Sum of zeroes $\alpha + \beta = -b/a$, Product $\alpha \beta = c/a$. Given $-b/a = c/a \Rightarrow -b = c$.
Sum of zeroes $= -2/k$, Product $= 3k/k = 3$. Given $-2/k = 3 \Rightarrow k = -2/3$. [1.0 Mark]
Correct Answer: (D) $-2/3$
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