NCERT Exemplar Solutions
Class 10 - Mathematics - CHAPTER 2: Polynomials - Exercise 2.1Question 7
Class 10 - Mathematics - CHAPTER 2: Polynomials - Exercise 2.1
Question. 7
The zeroes of the quadratic polynomial \(x^2 + 99x + 127\) are
(A)
both positive
(B)
both negative
(C)
one positive and one negative
(D)
both equal
Detailed Answer with Explanation:
Step 1: Recall the relations between coefficients and zeroes.
For quadratic polynomial \(ax^2 + bx + c\):
Sum of zeroes = \(-\dfrac{b}{a}\),
Product of zeroes = \(\dfrac{c}{a}\).
Step 2: Apply to the given polynomial.
Here, \(a = 1\), \(b = 99\), \(c = 127\).
So,
Sum = \(-\dfrac{99}{1} = -99\).
Product = \(\dfrac{127}{1} = 127\).
Step 3: Interpret the signs.
Since product \(127 > 0\), both zeroes must have the same sign.
Since sum \(-99 < 0\), the common sign must be negative.
Conclusion: Both zeroes are negative.