Last updated at May 29, 2018 by Teachoo

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Ex 2.1, 1 Which of the following expressions are polynomials in one variable and which are not? State reasons for your answer. (i) 4๐ฅ2 โ 3๐ฅ + 7 4๐ฅ2 โ 3๐ฅ + 7 = 4๐ฅ2 โ 3๐ฅ1 + 7 ๐ฅ0 Here power of equation is 2,1 and 0. Since all powers are whole number, it is a polynomial Now since there is only one variable x, it is polynomial in one variable Yes, this expression is a polynomial in one variable x. Ex 2.1, 1 Which of the following expressions are polynomials in one variable and which are not? State reasons for your answer. (ii) y2 + โ2 y2 + โ2 = y2+ โ2 y0 Here power of equation is 2 and 0. Since all powers are whole number, it is a polynomial Now since there is only one variable y, it is polynomial in one variable. Yes, this expression is a polynomial in one variable y. Ex 2.1, 1 Which of the following expressions are polynomials in one variable and which are not? State reasons for your answer. (iii) 3โ๐ก + t โ2 3โ๐ก + t โ2 = 3 ๐ก^(1/2) + t1 โ2 As the power of t is 1/2 , which is not a whole number. Therefore, this expression is not a polynomial. Ex2.1, 1 Which of the following expressions are polynomials in one variable and which are not? State reasons for your answer. (iv) y + 2/๐ฆ y + 2/๐ฆ = y1 + 2/๐ฆ1 = ๐ฆ1 + 2 ๐ฆ^(โ1) Power of y is 1 and -1, Since -1 is not a whole number, it is not a polynomial Ex 2.1, 1 Which of the following expressions are polynomials in one variable and which are not? State reasons for your answer. (v) ๐ฅ10 + ๐ฆ3 + ๐ก50 ๐ฅ10 + ๐ฆ3 + ๐ก50 Here power of equation is 10, 3 and 50. Since all powers are whole number, it is a polynomial Now since there are three variables ๐ฅ , ๐ฆ & ๐ก , it is not polynomial in one variable.

Chapter 2 Class 9 Polynomials

Concept wise

- Definition
- Degree & Coefficient of a polynomial
- Value of a polynomial at a given point
- Verifying Zeroes of a polynomial
- Finding Zeroes of a polynomial
- Remainder Theoram
- Check if factor
- Factorisation by middle term
- Factorisation by factor formula
- Factorizing cubic equation
- Identity I - IV
- Identity V
- Identity VI & VII
- Identity VIII

About the Author

Davneet Singh

Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 9 years. He provides courses for Maths and Science at Teachoo.