Thread: The quadratic formula

1. The quadratic formula

Use the quadratic formula to solve:

-4x^2 + 13x - 3 = 0

2. # infront of x^2 is a
infront on x is b
infront of nothing constant term is c

also make sure equation is in standard form which it is.

then fill into

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

3. Originally Posted by brentwoodbc
# infront of x^2 is a
infront on x is b
infront of nothing constant term is c

also make sure equation is in standard form which it is.

then fill into

x= -b sqrt (b^2 -4ac)
2a
Yes, I tried that but I didn't get the right answer.

4. make sure you keep track of negatives "2 neg. = pos."
also what is the given answer?

5. also its + the sqrt sorry so -b plus or minus the sqrt

6. I get x=1/4,3

7. I got 2 ± √6 instead of 7 ± 5√2.

EDIT: Sorry, I meant I got -13 ± √217/ -8 instead of 9 ± √89/ 2.

8. Originally Posted by Joker37
I got 2 ± √6 instead of 7 ± 5√2.
thats odd maybe someone else can chime in on this but I get

-13 +/- √121
-8

and 121 is a perfect square so

-13 +/- 11
-8

so

1/4 , 3