# Maths

X squared-(k+3)x+4k=0
Please help me find the value of k for which there are equal roots but of opposite sign

1. Let r be the root:
x²-(k+3)x+4k= 0 = (x-r)(x+r)=x²-r²
equating coefficients,
-(k+3)=0, k=-3
4k=-r², r=sqrt(3*4)=2√3
or the equation is
x²-12=0
Find k from the equation.

posted by MathMate

First Name

## Similar Questions

1. ### maths

If the roots of the eqn 1/(x+p) + 1/(x+p) = 1/r are equal in magnitude but opposite in sign, show that p+r=2r and that the product of the roots is equal to (-1/2) (p²+q²)
2. ### Maths

I have a maths exam tomorrow and am studying with a friend. We are working on a question and are getting two different answers. Could you please show us the right way to do it? 2(4x + 3)(4x - 3) - (4x + 3)squared p.s i couldn't
3. ### Maths

M squared is greater than or equal to 36 How to find m I only have one set of answers for m and that is m is greater than or equal to 6 How to find the second set? Working out please
4. ### maths

q1) 2cos2x is f(x) -square root3 is g(x) solve f(x)-g(x)=0 to get points of intersection in x is between 0 and 180degrees q2) a) write the equation cos2x + 8cosx+9=0 in terms of cosx and show that for cosx it has equal roots q2b)
5. ### maths

Show that the equation (1) divided by (x+1) - (x)divided by (x-2)=0 has no real roots Well, to begin, start with 1/(x+1-x). The x's cancel out because they are opposite signs, so now you have 1/1, or just 1. Then, you are dividing
6. ### math

what is the rule for greater than less than sign. The greater than sign, > , means that whatever is to the left of it is greater than what is to the right of the sign. The less than sign, < , is just the opposite. Whatever
7. ### Maths

Find the possible value of k if X^2+(k-2)X+K+1=0 has equal roots
8. ### maths

for the graph y= -(x-2)squared +1: Find the x intercepts please show all working :)
9. ### physics

Four charges with equal magnitudes of 6.50 x 10-15 C are placed at the corners of a rectangle. The lengths of the sides of the rectangles are 4.07 cm and 5.28 cm. Find the magnitude of the electric field at the center of the
10. ### Math

Find the shortcut. Solve these problems. Then find and explain a shortcut method for finding the answer. 52(Squared) - 42 (squared) = 82 (Squared) - 72 (Squared) = 122 (Squared) - 112 (Squared) = 312 (Squared) - 302 (Squared) =

More Similar Questions