Question

need some help with quadratics, any help?

Answer 1

could you post a quadratic equation?

Answer 2

using the factor form
-(x+3) (x-10)
have to get the x-intercepts, the Y, and vertex

Answer 3

That negative at the beginning is a bit of a problem

Answer 4

i know the xs are (-3,o) (10,0) but unsure of other parts

Answer 5

how so?

Answer 6

I'd like to be able to multiply it out

Answer 7

You say the x solutions are -3 and 10 but are you taking the leading negative sign into account?

Answer 8

oh ya.. hmm

Answer 9

any suggestions poojal?

Answer 10

maybe we should try a different problem first?

Answer 11

Okay - a problem that has the equation in the usual x^2 + bx + c =0 if at all possible.

Answer 12

ya, this next one has to be done in complete square form (so says the paper)
f(x)= x^2 - 4x +1

Answer 13

To complete the square
move non-x term to the right
Divide equation by coefficient of x^2
get coefficienlt of x, divide by 2, square it and add it to both sides.

Answer 14

f(x)= x^2 - 4x +1
x^2 - 4x = -1 (coeffient of x^2 is 1 so)
coefficient of x is -4 so
-4 divided by 2 is -2 then squared it is +4
x^2 - 4x +4= -5

(x-2)*(x-2) = -5

Answer 15

and on that part we use the factored form thing to get
x^2 -2x -2x +4
right?

Answer 16

oops forgot to add the =-5

Answer 17

No, I thought we carry out the square root
x -2 = sq root (+3)

Answer 18

how we do that?

Answer 19

Here's how we did it:

To complete the square
move non-x term to the right
Divide equation by coefficient of x^2
get coefficienlt of x, divide by 2, square it and add it to both sides.

Answer 20

f(x)= x^2 - 4x +1
x^2 - 4x = -1 (coeffient of x^2 is 1 so)
coefficient of x is -4 so -4 divided by 2 is -2 then squared it is +4

x^2 - 4x +4= 3
(x-2)*(x-2) = 5

Answer 21

i mean like how we carry out the square root?

Answer 22

f(x)= x^2 - 4x +1
x^2 - 4x = -1 (coeffient of x^2 is 1 so)
coefficient of x is -4 so -4 divided by 2 is -2 then squared it is +4
x^2 - 4x +4= 3
(x-2)*(x-2) = 3

Answer 23

Okay so we take square root of (x-2)*(x-2) which is x-2
and take the sq root of 3 so we have
x-2 = sq root (3)

Answer 24

ok, what would be the next step?

Answer 25

x = sqrt (3) + 2 and
x = sqrt (3) - 2

Is that okay for the answer or do they want you to use a calculator?

Answer 26

i can do the calculator, and thats the X-intercepts right?

Answer 27

and the -5 would be the Y?

Answer 28

Yes those are the x - intercepts

I think the 'y' is -3

Answer 29

ok and what would be the vertex??

Answer 30

vertex is at X=2 and y=-3
(I got that from my calculator http://www.1728.org/quadratc.htm)

Answer 31

ok, makes sense

Answer 32

thank you wolf, think that will be all for now, got to go to the store. see ya around wolf

Answer 33

okay - see ya