SOLUTION: If the discriminant of the quadratic equation kx^2-6x+1=0 is zero, then what is the value of k? Answer is : k=9 But how to solve it?

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Question 915796: If the discriminant of the quadratic equation kx^2-6x+1=0 is zero, then what is the value of k?
Answer is : k=9
But how to solve it?

Answer by rothauserc(4718) About Me  (Show Source):
You can put this solution on YOUR website!
we are given,
discriminant(D) of the quadratic equation kx^2-6x+1=0 is zero
D = square root(b^2 -4ac)
in our example, b = -6, a = k, c = 1, then
0 = square root(-6^2 - 4*k*1)
square both sides of = and combine like terms
0 = 36 - 4k
add 4k to both sides of =
4k = 36
k = 9