Use the quadratic formula to find the roots of f(x) = -4x^2-6x+2. Please explain. Thanks a lot!?

Answer 1

your equation is in the form f(x)=ax^2+bx+c

that means, a=-4, b=-6, c=2.

Now plug that into the quadratic formula.

I got x= -3/2 and x=1/2

Answer 2

http://answers.yahoo.com/question/index;_ylt=Au3lMz2q_67k5hD_Op.cVyXsy6IX;_ylv=3?qid=20071024155050AAQSVMo
ya

Answer 3

First, take out the common factor and the minus. The expression becomes : f(x) = -2(2x^2 + 3x - 2) Much easier to solve now, go do it.

Well try f(x) = -2(2x - 1) (x + 2)
For f(x) to = 0 x must = 1/2 or -2 (if my workings are right)
Expand my factors and see if you come out with the original equation.

Answer 4

Standard form of a quadratic is
f(x)=ax^2+bx+c

so in our case
a=-4
b=-6
c=2

The quadratic formula is

x=(-b+/-sqrt(b^2-4ac))/(2a)

plug in values for a, b, and c.
x=(-(-6)+/-sqrt((-6)^2-4(-4)(2)))/(2(-4))
x=(6+/-sqrt(36-32))/(-8)
x=6+/-sqrt(4)/(-8)
x=(6+/-2)/(-8)
x=(6+2)/(-8) and x=(6-2)/(-8)
x=8/(-8) x=4/(-8)
x=-1 x=-1/2

Answer 5

quadratic formula= -b(pos/neg) squareroot of (b^2-4ac) divided by 2(a)

so, using the formula,

-(-6)(pos/neg)squareroot of ((-6)^2-4(-4*2)
divided by 2(-4)


leaving

6(pos/neg)squarerootof(68) divided by -8


68div 4 =17, right?


so we can replace

6(pos/neg) squareroot of(17*4) div by -8


resulting to

6(pos/neg) 2 squareroot of 17
div -8

.
taking the positive part,
x= - (6+2sqr17)/8

taking the negative part,
x= - (6-2sqr17)/8



i hope that helps. good luck!

Answer 6

-b+-sqrt(b^2-4ac) quadratic equation

6+or-sqrt(36-4(-4)(2))/-8 numbers plugged in

6+-2sqrt(17)/-8 simplify

3+-sqrt(17)/-4 simplified again

Zeros: 3+sqrt(17)/-4

3-sqrt(17)/-4

Answer 7

f(x)= -2(2x^2 + 3x -1)

for f(x) to =0 then
2x^2 +3x-1 must =0
and
2x^2+3x equals 1
dividing both sides by x
2x +3 equals 1/x
2x-1/x equals -3

Answer 8

f(x) = -4x^2-6x+2
x = [6 +/- sqrt( 6^2 -4(-4)(2))]/(2(-4))
x = [6 +/- sqrt (68)]/-8
x = [6 +/- 2sqrt(17)]/-8
x = [3 +/- sqrt(17)]/-4

Answer 9

x=(-b(+or-)(b^2 - 4ac)^0.5)/2a

here a=-4
b=-6
c=2

x=6(+or-)(36+32)/-8

x=(6+68)/-8 = -9.25

or x= (6-68)/-8= 7.75