Question

Question 5 - 3

Q5. Find the value(s) of k which each of the following quadratic equation has equal roots:
(iii) (k - 4)x² + 2(k - 4)x + 4 = 0

Answer 1

Dear student

For equal roots, b² - 4ac = 0

Here, a = k - 4, b = 2k - 8, c = 4

So, b² - 4ac = 0 shows that,

{2k - 8}² - 4 x {k - 4} x 4 = 0

ie, 4k² - 32k + 64 - 16{k - 4} = 0

ie, 4k² - 32k + 64 - 16k + 64 = 0

ie, 4k² - 48k + 128 = 0

ie, k² - 12k + 32 = 0

On solving, we get,

k = 8, 4
Regards