January 2005
6663 Core Mathematics C1 Mark Scheme Scheme
Question
Marks
number
1.
(a) 4
(or ±4) --
Bl
1
(b) 16 2
-
—j- and any attempt to find 162
Ml
162 — (or exact equivalent, e.g. 0.015625) 64
(or ± —) 64
Al
(3) 3
2.
(i)(a)15x2+7
Ml Al Al
(3)
(i) (b) 30*
Blft
(1)
3
3
(ii) x + 2x2+x~l + C
Al:x+C, A1:+2jc2, A1:+x~'
Ml Al Al Al(4) 8
3.
Attempt to use discriminant b2 - Aac (Need not be equated to zero)
Should have no jc's
Ml
(Could be within the quadratic formula)
144_4xJtx£=0 or Jl44-4xkxk = 0
Al
Attempt to solve for k
Ml
(Could be an inequality)
k=6
Al
(4)
4 4.
x2+2(2-x) = 12
or
(2-y)2+2y = l2
x2-2x-8 = 0
or
y2-2y-S = 0
(Eqn. in x or j; only)
(Correct 3 term version)
Ml Al
(Allow, e.g. x2-2x = 8) (x-4)(x + 2) = 0
x = 4,
x=...
x = -2
y = -2, y = 4
or
(y-4)(y + 2) = 0
or
y = 4, y = -2
or
x = -2, x = 4
y= ...
Ml
Al
(M: attempt one, A: both)
Ml Alft
(6) 6