Vatsal
  • 5

Mathematics

  • 5

For what value of k (4-k)x^2+(2k+4)x+(8k+1)=0 is a perfect square?

Share

1 Answer

  1. For a perfect square, put D = b^2 – 4ac = 0

    [2k + 4]^2 – 4 [4 – k] [8k + 1] = 0
    4k^2 + 16 + 16k – 4 [32k + 4 – 8k^2 – k] = 0
    4k^2 + 16 + 16k – 128k – 16 + 32k^2 + 4k = 0
    36k^2 – 108 k = 0
    k^2 – 3k = 0
    k(k – 3) = 0
    k = 0 or k = 3

    • 1
Leave an answer

Leave an answer

Browse