Multiple choice

For what value of $k$ will the quadratic equation: $\displaystyle { kx }^{ 2 }+4x+1=0$ have real and equal roots ?

  1. 2

  2. 3

  3. 4

  4. 1
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

For real and equal roots, the discriminant D = b^2 - 4ac = 0. Here a=k, b=4, c=1. 4^2 - 4*k*1 = 0. 16 - 4k = 0. 4k = 16, k = 4.

AI explanation

For the quadratic equation to have real and equal roots, its discriminant (b^2 - 4ac) must equal zero. Substituting a = k, b = 4, and c = 1 gives 4^2 - 4(k)(1) = 0. Simplifying this yields 16 - 4k = 0, which means 4k = 16, so k = 4.

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