Let 3x^2 + 4x + c = 0/ What value of c with give us exactly one solution for x?

I am not sure how exactly to complete these kind of problems.

Thanks in advance.

Guest Feb 13, 2018

#1**+2 **

If we have only one solution ...the discriminant will = 0

So a = 3 , b = 4 and c = ???

The discriminant is given by :

b^2 - 4ac so.... plugging in, we have that

4^2 - 4(3)(c) = 0

16 - 12c = 0

16 = 12c divide both sides by 12

16/12 = c = 4/3

Here's the graph that confirms one solution :

https://www.desmos.com/calculator/1ldxjsdqjn

CPhill Feb 13, 2018