Question 20 Due to heavy storm an electric wire got bent as shown in the figure. It followed a mathematical shape. Answer the following questions below.Question 20 (i) Name the shape in which the wire is bent (a) Spiral (b) ellipse (c) linear (d) ParabolaParabola
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Question 20 (ii) How many zeroes are there for the polynomial (shape of the wire) (a) 2 (b) 3 (d) 1 (d) 0Since polynomial hits the x-axis at 2 points
∴ Number of zeros = 2
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Question 20 (iii) The zeroes of the polynomial are (a) –1, 5 (b) –1, 3 (c) 3, 5 (d) –4, 2Zero of polynomial would be where curve touches the x-axis
∴ Zeroes are −1 and 3
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Question 20 (iv) What will be the expression of the polynomial? (a) x2 + 2x – 3 (b) x2 – 2x +3 (c) x2 – 2x – 3 (d) x2 + 2x + 3Since Zeroes are −1 and 3
Polynomial = (x − (−1)) (x − 3)
= (x + 1) (x − 3)
= x (x − 3) + 1 (x − 3)
= x2 − 3x + x − 3
= x2 − 2x − 3
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Question 20 (v) What is the value of the polynomial if x = –1? (a) 6 (b) –18 (c) 18 (d) 0At x = −1
Value of Polynomial is 0
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Made by

Davneet Singh

Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 12 years. He provides courses for Maths and Science at Teachoo.