SOLUTION: I am supposed to find k in the following quadratic equation: (k+3)x^2 + 2kx + 4 = 0. I have tried using the quadratic formula and unless I'm doing something wrong I don't com

Question 109585: I am supposed to find k in the following quadratic equation:
(k+3)x^2 + 2kx + 4 = 0.
I have tried using the quadratic formula and unless I'm doing something wrong I don't come up with k. I have tried using the discriminant to find k with no success. I must be missing something easy.
Thanks for your help, Don
Found 2 solutions by jim_thompson5910, edjones:
Answer by jim_thompson5910(35256) (Show Source): You can put this solution on YOUR website!
Are you trying to find a k that yields one real solution? If you are, then the discriminant must equal zero. So

which means

Solved by pluggable solver: Quadratic Formula

Let's use the quadratic formula to solve for k:

Starting with the general quadratic

the general solution using the quadratic equation is:

So lets solve ( notice , , and )

Plug in a=4, b=-16, and c=-48

Negate -16 to get 16

Square -16 to get 256 (note: remember when you square -16, you must square the negative as well. This is because .)

Multiply to get

Combine like terms in the radicand (everything under the square root)

Simplify the square root (note: If you need help with simplifying the square root, check out this solver)

Multiply 2 and 4 to get 8

So now the expression breaks down into two parts

or

Lets look at the first part:

Add the terms in the numerator

Divide

So one answer is

Now lets look at the second part:

Subtract the terms in the numerator

Divide

So another answer is

So our solutions are:

or

So if k=-2 or k=6, then it will give us one solution for
Answer by edjones(8007) (Show Source): You can put this solution on YOUR website!
(k+3)x^2 + 2kx + 4 = 0.
kx^2+3x^2+2kx+4=0
kx^2+2kx=-3x^2-4
k(x^2+2x)=-3x^2-4
k=(-3x^2-4)/(x^2+2x)
Ed

RELATED QUESTIONS
How can i solve for x using quadratic equation?? 2(1-k)x^2-4kx+k=0 im having... (answered by stanbon,MathTherapy)
Okay, First of all here is the question. "Graph the following quadratic equation {{{... (answered by lwsshak3)
f(x) = x^3 + (1 - k^2)x + k (a) Show that -k is a root of f. I've already solved this (answered by jsmallt9)
Let K be a real number, and consider the quadratic equation (k+1)x^2+4kx+2=0 a. Show... (answered by robertb)
Find the number k for which the quadratic equation x^2+kx+k=0 has no real solutions.... (answered by josgarithmetic)
Find k if the following equations have a double root: kx^2+4x+3=0 I know that this... (answered by josgarithmetic,MathTherapy)
Find the value(s) of k such that the quadratic (k+1)x^2+2kx+2k=3(kx-1) has roots whose... (answered by thesvw)
Please help me solve this problem: Find the equation of the line with slope -1 that is... (answered by MRperkins)
what are the solutions to this equation using the quadratic formula? X^+12=7x? i have... (answered by scott8148)