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Last updated at Aug. 1, 2017 by Teachoo

Transcript

Ex 2.4, 2 Find a cubic polynomial with the sum, sum of the product of its zeroes taken two at a time, and the product of its zeroes as 2, –7, –14 respectively. Let cubic polynomial be p(x) = ax3 + bx2 + cx + d Sum of zeroes Sum of zeroes = 2 (−𝑏)/𝑎 = 2 Assuming a = 1 (−𝑏)/1 = 2 b = −2 Sum of product of zeroes Sum of product of zeroes = −7 𝑐/𝑎 = −7 Assuming a = 1 𝑐/1 = −7 c = −7 Product of zeroes Product of zeroes = −14 (−𝑑)/𝑎 = − 14 𝑑/𝑎 = 14 Assuming a = 1 𝑑/1 = 14 d = 14 Thus, a = 1, b = –2 , c = –7, d = 14 Hence, p(x) = ax3 + bx2 + cx + d = x3 – 2x2 − 7x + 14

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.