0 reads0 ratings0 helpful
If the sum of the zeroes of the polynomial \(p(x)=2x^2+kx+8\) is \(3\), what is the value of \(k\)?
Advertisement
Answer and explanation
Correct answer: -6
For a quadratic polynomial \(ax^2+bx+c\), the sum of its zeroes is \(-\frac{b}{a}\). Here, \(a=2\) and \(b=k\), so \(-\frac{k}{2}=3\), which gives \(k=-6\). Exam tip: use \(-b/a\) for the sum of zeroes; \(c/a\) gives their product, not their sum.
Frequently asked questions
What is the correct answer to this question?
-6
Why is this the correct answer?
For a quadratic polynomial \(ax^2+bx+c\), the sum of its zeroes is \(-\frac{b}{a}\). Here, \(a=2\) and \(b=k\), so \(-\frac{k}{2}=3\), which gives \(k=-6\). Exam tip: use \(-b/a\) for the sum of zeroes; \(c/a\) gives their product, not their sum.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Polynomials. Topic: Polynomials in one variable.
Student feedback
Was this question useful?
Was this question useful?
👍 0 Helpful 👎 0 Not helpful
Difficulty
Easy0%
Medium0%
Hard0%
Was the explanation clear?
Yes 0% No 0%
0 responsesStudent Reviews
No published reviews yet.
Advertisement