RD Sharma - Mathematics

Book: RD Sharma - Mathematics

Chapter: 2. Polynomials

Subject: Maths - Class 10th

Q. No. 35 of CCE - Formative Assessment

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35

For what value of k, is – 2 a zero of the polynomial 3x2 + 4x + 2k?

Given,


Polynomial 3x2 + 4x + 2k


Zero of the polynomial = – 2


As we have zero,


f(x) = 3x2 + 4x + 2k = 0


By putting x = – 2


f( – 2) = 3( – 2)2 + 4 ( – 2) + 2k = 0


f( – 2) = 12 – 8 + 2k = 0


= 4 + 2k = 0


= 2k = – 4


k = – 4/2 = – 2


So we have the value of k = – 2


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?