If (r=0), what will be the degree of (rx^9+2x^4-3)?
Answer and explanation
Correct answer: 4
On substituting \(r=0\), \(rx^9=0\cdot x^9=0\). The polynomial becomes \(2x^4-3\). The highest power of \(x\) in this remaining polynomial is 4, so its degree is 4. Degree 9 belongs only to the original possible term; it is not counted when its coefficient is zero. Exam tip: remove all zero-coefficient terms before identifying the highest exponent.
Frequently asked questions
What is the correct answer to this question?
4
Why is this the correct answer?
On substituting \(r=0\), \(rx^9=0\cdot x^9=0\). The polynomial becomes \(2x^4-3\). The highest power of \(x\) in this remaining polynomial is 4, so its degree is 4. Degree 9 belongs only to the original possible term; it is not counted when its coefficient is zero. Exam tip: remove all zero-coefficient terms before identifying the highest exponent.
Which subject and chapter does this question cover?
This is a Class 9 Mathematics question. Chapter: Introduction to Polynomials. Topic: Degree of a Polynomial.
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