Alevel_C1C2
Alevel_C1C2
Alevel_C1C2
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
4.<br />
16<br />
y<br />
14<br />
12<br />
10<br />
B4<br />
y = x 2<br />
8<br />
6<br />
4<br />
y = 8 – 2x<br />
2<br />
O<br />
4<br />
x<br />
Subtract from both sides of the equation x<br />
2x – 8 then x 2 = 8 - 2x.<br />
Solutions are x = 2, x = -4<br />
2<br />
+ 2x<br />
− 8 = 0<br />
B1<br />
A2<br />
7<br />
5. (a) Equal roots then the discriminant = 0. M1<br />
a 2 − 4× 4× 9 = 0<br />
B1<br />
a 2 = 16 × 9<br />
a < 0∴ a = −12 A1 (3)<br />
2<br />
(b) ( 3k)<br />
− 4× 9× k = 0<br />
B1<br />
2<br />
9k<br />
− 36k<br />
= 0<br />
B1<br />
9kk<br />
( − 4)<br />
= 0<br />
M1<br />
k ≠ 0∴ k = 4 A1 (4)<br />
7<br />
© Oxford University Press 2008<br />
Core C1
Change language