Question

Find value of k for which the eqadratic equation x2+K(2x+k-1)+2=0 has real and equal roots.

Answer 1

Hi ,

x² + k ( 2x + k - 1 ) + 2 = 0

x² + 2kx + ( k² - k + 2 ) = 0

compare above quadratic equation with

ax² + bx + c = 0

a = 1 , b = 2k , c = k² - k + 2

It is given that roots are real and equal.

discreaminant = 0

b² - 4ac = 0

( 2k )² - 4 × 1 × ( k² - k + 2 ) = 0

4k² - 4k² + 4k - 8 = 0

4k - 8 = 0

4k = 8

k = 8/4

k = 2

I hope this helps you.

:)