RD Sharma - Mathematics

Book: RD Sharma - Mathematics

Chapter: 2. Polynomials

Subject: Maths - Class 10th

Q. No. 19 of CCE - Formative Assessment

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19

If x = 1 is a zero of the polynomial f (x) = x3 – 2x2 + 4x + k, write the value of k.

Given,


f(x) = x3 – 2x2 + 4x + k


x = 1 is a zero,


So,


Keeping x = 1 we get,


f(1) = 13 – 2(1)2 + 4×1 + k


f(1) = 1 – 2 + 4 + k


f(1) = 5 – 2 + k


f(1) = 3 + k


– 3 = k


So we get,


k = – 3


Chapter Exercises

More Exercise Questions

8

The sum and product of the zeros of a quadratic polynomial are and — 3 respectively. What is the quadratic polynomial?