Question

will someone please teach me how to find the discriminant of the following equation?
9x^2+12x+4=0

Answer 1

for an equation of the form\[ax^2+bx+c=0\]the discriminant is\[b^2-4ac\]

Answer 2

so what would this equation look like, in that form?

Answer 3

Fill in the numbers, he gave you the variables that match up with the equation you gave us. It is all just substitution.

Answer 4

if a=9 then what is b=? and c=?

Answer 5

b=12 and c=4?

Answer 6

correct! now fill in the equation b^2−4ac to find the discriminant

Answer 7

Once you have the numbers substituted in the correct places..it is just simple math solving and simplifying.

Answer 8

When you have the answer I can check it for you.

Answer 9

okay but i still am not to sure. I see where you did that but if i filled out b^2-4ac then would that be 12^2-4?

Answer 10

you forgot to fill in the (a)(c) part after the 4...

Answer 11

so 12^2-4(12)(4)? sorry about this... for some reason i am so lost in this.

Answer 12

close, if a=9 b=12 and c=4 you should have gotten 12^2-4(4)(9).

Answer 13

okay i see that now thank-you for clearing that up! so the answer would be 12^2-4(4)(9)

Answer 14

do the math, simplify and you should get your answer

Answer 15

Did you get an answer?

Answer 16

12^2-144?

Answer 17

almost done solving! you need to simplify more. what is 12^2? then subtract 144 from the answer you get.

Answer 18

so it =0!!

Answer 19

Correct!!
Here is a short explanation. What you are having trouble solving is easier than you think ^.^ I hope you understand!

Answer 20

i do now thanks to u!

Answer 21

OH and in my drawing i mixed up the (a) and (c) but when you are solving the equation it usually does not affect your solution.

Answer 22

ok that is fine