Question
Mathematics Question on Polynomials
Assertion (A): Zeroes of a polynomial p(x)=x2−2x−3 are -1 and 3.
Reason (R): The graph of polynomial p(x)=x2−2x−3 intersects the x-axis at (-1, 0) and (3, 0).
Both, Assertion (A) and Reason (R) are true. Reason (R) explains Assertion (A) completely.
Both, Assertion (A) and Reason (R) are true. Reason (R) does not explain Assertion (A).
Assertion (A) is true but Reason (R) is false.
Assertion (A) is false but Reason (R) is true.
Both, Assertion (A) and Reason (R) are true. Reason (R) explains Assertion (A) completely.
Solution
- The given polynomial is p(x)=x2−2x−3. To find the zeroes, we solve x2−2x−3=0 by factoring:
x2−2x−3=(x−3)(x+1)=0
Thus, the zeroes of the polynomial are x=3 and x=−1.
- The graph of a quadratic polynomial intersects the x-axis at its zeroes. Therefore, the points where the graph intersects the x-axis are (−1,0) and (3,0), as given in the reason.
Since both the assertion and the reason are true, and the reason explains the assertion, the correct answer is (a).