Find the value(s) of k for which the quadratic equation
x 2 + 2√2 kx + 18 = 0 has equal roots

CBSE Class 10 Sample Paper for 2020 Boards - Maths Standard
CBSE Class 10 Sample Paper for 2020 Boards - Maths Standard
Last updated at Dec. 16, 2024 by Teachoo
Transcript
Question 20 Find the value(s) of k for which the quadratic equation x2 + 2β2 ππ₯ + 18 = 0 has equal roots x2 + 2β2 ππ₯ + 18 = 0 Comparing equation with ax2 + bx + c = 0 a = 1, b = 2β2k , c = 18 Since the equation has 2 equal roots, D = 0 b2 β 4ac = 0 Putting values (2β2k)2 β 4 Γ 1 Γ 18 = 0 22 Γ (β2)^2Γ k2 β 72 = 0 4 Γ 2 Γ k2 = 72 8k2 = 72 k2 = 72/8 k2 = 9 k = Β± β9 k = Β± 3