Maths Question!! Please help?

jldesign

Hi,

I can't figure out for the life of me how to do this question, would anyone be kind enough to show me or explain to me how to do this, PLEASE.



Thanks in advance

smiles_1998

Hey...sorry if this is too late (I had to find my Maths copy with these questions in them!) but here is how I did these questions:
12.i.
f(x)= x²+bx+c
f(0)=-3 (I am using the (0,-3) coordinate here)
(0)²+b(0)+c=-3
0+0+c=-3
c=-3

12.ii.
f(-3)=0
x²+bx+c=0
(-3)²+b(-3)+c=0
(-3)²+-3b+-3=0
(-3)²-3b-3=0
-3b+6=0
-3b=-6
3b=6
b=6 divided by 3
b=2

12.iii
x²+bx+c=0
x²-2x-3=0
(x+1)(x-3)
d= (1,0) (Sorry about the short answer here- can't quite remember how I did this one)

14.i.
y=x²+bx+c
-2=0²+b(0)+c
-2=c

-3=(1)²+b(1)-2
-3=1+b-2
-3=-1+b
-3+1=b
-2=b

14.ii.
y=(2)²+-2(2)+(-2)
y=4-4-2
y=-2

Sorry if this is really all over the place- I would upload a photo of the answers in my Maths copy but the answers there are even more of a mess (and they are all spread out on loads of pages)!