Write a polynomial of degree 3 in the variable x, in which the coefficient of the x² term is - 7. Class 9

Write a polynomial of degree 3 in the variable x, in which the coefficient of the x² term is - 7. Class 9

Question 1.

Write a polynomial of degree 3 in the variable x, in which the coefficient of the x² term is - 7. Class 9

Solution:

2x³ - 7x² + 3x - 5

[Note: The above problem has many solutions. Students may write other than the one given.]

Question 2.

Find the values of the following polynomials at the indicated values of the variables. Class 9

i. 5x² - 3x + 7 if x = 1

ii. 4t³ - t² + 6 if t = a

Solution:

5x² - 3x+ 7

Substituting x = 1, we get

5(1)² - 3(1) + 7 = 5(1) - 3 + 7

= 5 - 3 + 7 = 9

ii. 4t³ - t² + 6

Substituting t = a, we get

4(a)³ - (a)² + 6 = 4a³ - a² + 6