SOLUTION: find the value of k for which the roots are real and equal in the equation 12x^2+4kx+3=0

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Question 763896: find the value of k for which the roots are real and equal in the equation 12x^2+4kx+3=0
Answer by fcabanski(1391) About Me  (Show Source):
You can put this solution on YOUR website!
For the roots of a quadratic equatioin (ax^2 +bx + c) to be equal and real, the discriminant of the equation must be 0. The discriminant is the part under the square root sign in the quadratic formula:


b^2 - 4ac


For this equation b= 4k, a=12 and c=3


%284k%29%5E2+-+4%2A12%2A3+=+0


16k%5E2+-+144+=+0


16k%5E2+=+144


k%5E2+=+9


k = 3 or -3


A k value of 3 or -3 results in two real roots that are equal.