Question 2 (OR 2 nd question)

Find the value(s) of k for which the equation x 2 + 5kx + 16 = 0 has real and equal roots

Find value of k for which equation x^2 + 5kx + 16 = 0 has real and

Question 2 (Or 2nd) - CBSE Class 10 Sample Paper for 2019 Boards - Part 2


Transcript

Question 2 (OR 2nd question) Find the value(s) of k for which the equation x2 + 5kx + 16 = 0 has real and equal roots x2 + 5kx + 16 = 0 Comparing equation with ax2 + bx + c = 0 a = 1, b = 5k , c = 16 Since the equation has 2 equal roots, D = 0 b2 – 4ac = 0 Putting values (5k)2 – 4 × 1 × 16 = 0 25k2 – 64 = 0 25k2 = 64 k2 = 64/25 k2 = 8^2/5^2 k2 = (8/5)^2 k = ± √((8/5)^2 ) k = ± 8/5 ∴ k = ± 8/5

Go Ad-free
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.