CBSE Class 10 Sample Paper for 2022 Boards - Maths Standard [MCQ]

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Question 38 - CBSE Class 10 Sample Paper for 2022 Boards - Maths Standard [MCQ] - Solutions of Sample Papers for Class 10 Boards

Last updated at April 16, 2024 by

If 2 and ½ are the zeros of px 2+5x+r, then

(a) p = r = 2   (b) p = r = −2   (c) p = 2, r= −2       (d) p = −2, r = 2

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Question 38 If 2 and ½ are the zeros of px 2+5x+r, then (a) p = r = 2 (b) p = r = −2 (c) p = 2, r= −2 (d) p = −2, r = 2 Let p(x) = px2 + 5x + r Since 2 and ½ are zero of p(x) p(2) = 0 p(2)2 + 5(2) + r = 0 4p + 10 + r 4p + r = −10 p(𝟏/𝟐) = 0 p (𝟏/𝟐)^𝟐+ 5 (𝟏/𝟐) + r = 0 𝒑/𝟒+𝟓/𝟐+𝒓 = 0 Multiplying by 4 both sides p + 10 + 4r = 0 p + 4r = − 10 Since only p = r = −2 satisfies both equations So, the correct answer is (b)

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Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 14 years. He provides courses for Maths, Science and Computer Science at Teachoo