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

CBSE Class 10 Sample Paper for 2022 Boards - Maths Basic [MCQ] →
Class 10
Solutions of Sample Papers for Class 10 Boards

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

Slide83.jpeg

Slide84.jpeg

Transcript

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)

Ask a doubt
Davneet Singh's photo - Co-founder, Teachoo

Made by

Davneet Singh

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, Social Science, Physics, Chemistry, Computer Science at Teachoo.