MATHEMATICS
PAPER ONE(P1)
GRADE 12 
EXAM PAPERS AND MEMOS
SEPTEMBER 2016

NOTE:

  • If a candidate answered a question TWICE, mark the FIRST attempt ONLY.
  • Consistent accuracy applies in ALL aspects of the memorandum.
  • If a candidate crossed out an attempt of a question and did not redo the question, mark the crossed-out attempt.
  • The mark for substitution is awarded for substitution into the correct formula.

MEMORANDUM

QUESTION 1

1.1.1

?− 4?−12=0
(? − 6)(? + 2)=0
? = 6 or ? = −2

✔ standard form
✔ ?=6 (CA applies)
✔ ?=−2 (CA applies)

(3)

     

1.1.2

3?2+2?−6=0
?=−(2) ± √(2)− 4(3)(−6)
                2(3)
?=−2 ± √766
?=−1,79 or ?=1,12

 Penalise 1 mark for incorrect rounding off.

✔ substitution

✔ x = −1,79 

✔ x = 1,12 

(3)

     

1.1.3 

 3?− 1 = 27-x
                 3
3?− 1 = 3−3? −1
∴ ?− 1=−3? − 1
?+ 3? = 0
? (?+3) = 0
? = 0 or  ? = −3

OR

3?− 1 = 27 − ?3
3?− 1.3 = 27−?
3?−1 + 1 = 3−3?
∴ ?2=−3?
?+ 3? = 0
?(?+3) = 0
?=0 or ?=−3

✔ 3−3?−1 
✔ equating exponents
✔factors/faktore 
✔ both x-values

 

 

 

✔?−1 + 1 = 3−3?
✔equating exponents 
✔ factors/faktore 
✔both x-values

(4)

1.2.1 1 +1/? = 0
? + 1 = 0
   ? 
? =−1 or  ?=0

✔ ? =−1
✔ ?=0

(2)

     
1.2.2 ?−1/?  =1
1+1/?
? −1/?=1 +1/?
?− 1 = ? + 1
?− ? − 2 = 0
(?+1)(?−2) = 0
?=−1 or ?=2
?=2 only

✔ manipulation of equation 
 ✔ standard form
✔ factors
✔ both x-values
✔ choosing x = 2 

(5) 
[17]

QUESTION 2   
2.1

? − ? =3 ; ?? = 28
? − ? = 3…………………..(1)
?? = 28………………… (2)
From (1) ? = ? + 3
Substitute in (2)
?(?+3) = 28
?+ 3? − 28 = 0
(?−4)(?+7)  =0
?=4 or  ?=−7
?=7 or  ?=−4

OR

From  (1) ? = ?−3
Substitute in (2)
?(?−3) = 28
?− 3? − 28 = 0
(?+4)(?−7) = 0
?=−4 or  ?=7
?=−7 or  ?=4

✔ ? = ? + 3
✔ substitute in (2)
✔ standard form
✔ factors
✔ y-value
✔ x-values

 

 

✔ ? = ? − 3✔ substitute in (2)
✔ standard form
✔factors
✔ x-values
✔ y-values

(6)

     
2.2 ?2  ≤ 4 + 3? ; ? > 0
?− 3? − 4 ≤ 0 
(?+1)(?−4) ≤ 0
you
Solution −1 ≤ ? ≤4
But ? >0
0 < ? ≤ 4

✔ standard form/standaardvorm
✔ factors/faktore 
✔ solution/oplossing  
−1 ≤ ? ≤4
✔ final answer/finale antwoord 
0 < ? ≤ 4

(4) 
[10]

QUESTION 3   
3.1 wow

?= ??+ ?? + ?
2? = 2
? =1
3? + ? = 2
3 + ? = 2
? = −1
? + ? + ? = 1 
1 − 1 + ? =1
? =1
?= ?− ? + 1
Row 80 Term 1
?80 = 80− 80 + 1
?80 = 6321

✔ a = 1 
✔ b = −1 
✔ c = 1 
✔ ?= ?− ? + 1
✔ 6321 

(5)

     
3.2

Row 80
6321 6323 6325 6327 ...
??=?/2[2(?) + (? − 1)?]
?80 80/2 [2(6321)+(80−1)(2)] Row 80
?80 = 512000

OR

Row 80 Term 80
?80 = 6321 + (79×2)
?80 = 6479
?= ?2[? + ?]
?80 = 80/2[6321 + 6479] Row 80
?80 = 512000

OR

TO THE EG
2? = 2
? = 1
3? + ? = 4
3 + ? = 4
? = 1
?  + ? + ? = 1
1 + 1 + ? = 1
? = −1

?= ?+ ? − 1
?? = ?2+ ? − 1
?80 = 80+ 80 −1
?80 = 6479
??= ?/2[?+?]
?80=80/2[6321+6479] Row 80
?80=512000

✔ n= 80 
✔ d = 2 
✔ sub into correct formula   
✔ answer(4) 

 

 

 

✔ calculating term 80 of row  
✔ 6479 
✔ sub into correct formula 
✔ answer (4)

 

 

 

 

 

 

 

 

✔ ?= ?+ ? − 1
✔ ?80 = 6479
✔ sub into formula
✔ answer 

(4) 
[9]

QUESTION 4   
4.1.1   ?10 = ?10 − ?9
?10 = 10(11)(12) − 9(10)(11)
?10 = 330
 ✔ setting up of equation

✔ substitution
✔ answer

(3)

     
4.1.2

? ;3? ;5? ;……………
? = 2?
??=?/2[2? + (? − 1)?]
??=?/2[2? + (? − 1)2?]
??=?/2(2? + 2?2−2?)
??=?3

OR


? = ?
? = 2?− ?
?? = ?/[? + ?]
??=?/2[?+2?− ?]
??=?3

✔ first three terms
✔ ? = 2?
✔ substitution
✔ answer (4) 

 

 

 

✔ ? = ?
✔ ? = 2?− ?
✔ substitution
✔ answer 

(4) 
[7]

  QUESTION 5 
5.1

? = ?+2
       ?
?3 = (?+2)2
           ?

Answer Only 2/2 

✔ ratio
✔ answer

(2)

     
5.2

?∞=  ?  
     1−?
−8=       ?       
        1 − (?+2)/?
−8=     ?          
        ?−?−2
?2=16
?  = ±4

- 1 MARK FOR (±) 
✔ substitution
✔ simplification
✔ ?2=16

✔ both answers 

(4) 
[6]

QUESTION 6   
6.1 ? = ?(1−?)?
? = 635000(1−15/100)5
? = 281 752,87

✔ ?=15/100 and ? =5
✔ sub into correct formula
✔ answer

(3)

     
6.2.1 ?? = ?[1 − (1+?)−?]
                ?
50000 = ?[1− (1 + 16.75/1200)−48]      
                       16.75/1200
? = ? 1 436,29

✔ ?=16.75/1200
✔ ?=−48
✔ sub into correct formula
✔ answer

(4)

     
6.2.2

?? = ?[1 − (1+?)−?]
                ?
?? = 1436.29 [1 − (1+16.75/1200)−18]
                          16.75/1200
?? = ?22 721,97704
?? = ?22 722

OR

Outstanding balance (OB)
OB = 50000(1+ 16.75/1200)30[1436.29 [(1 + 16.75/1200)30−1]]
                                                                     16.75/1200
OB =  ? 22722,14
OB = ?22722

✔ ?=−18
✔ ?=16.75/1200
✔ substitution
✔ answer
✔ rounding

(5)

✔ ?=30
✔ ?=16.75/1200
✔ sub into both formulae
✔ answer
✔ rounding

(5)

     
 6.3  ? = ?(1+?)?
? = 2? and ? = ?
2? = ?(1+14.75/100)?
? =        log2            
       log(1 +14.75/100)
? = 5.04 ?????

✔ ? = 2? and ? = ?
✔ sub into correct formula
✔ using of logs
✔ answer

(4)
[16]

QUESTION 7
7.1.1 x = 0

✔answer 

(1)

     
7.1.2 x > -2 ; x # 0

✔x > -2
✔x # 0

(2)

     
7.1.3 y = -4

✔answer 

(1)

     
7.1.4 ? = ?− 4
5 = ?− 4
?= 9
? = ±3
? = 3?−4

✔ sub of −4
✔ sub of point (2;5)
✔ ? = ±3
✔ answer with correct ? value

(4)

     
7.1.5 x = -2
y = -1

✔x = -2
✔y = -1

(2)

     
7.1.6 ? =    ?     −1
      ?+2
−3 =   ?    − 1
        0+2
?=−4
?=  −4   − 1
     ?+2

✔ sub of asymptotes
✔ sub of point (0;-3)
✔ ?=−4

(3)

     
7.1.7 ? = ? + 2 −1
? = ? + ?
? = −(? + 2) −1
? = −? − ?

✔? = ? + ?
✔? = −(? + 2) −1
✔? = −? − ?

(3)

     
 7.2.1  ? = log½?
?−1 ∶ ?= log½?
? = (½)?
OR
? = 2−?

✔swopping of x and y
✔answer

(2)

     
7.2.2 7.2.2

✔Shape 
✔y-intercept
✔any other correct point

(3)

     
7.2.3

g(x) = (½)-x

OR

g(x) = 2x

✔✔Answer

✔✔Answer

(2)

     
7.2.4 x > 1

✔✔x > 1

(2)
[25]

QUESTION 8
8.1 x = -3

✔x = -3

(1)

     
 8.2  ? = ?(? + 3)− 5
4 = ?(9) − 5
9? = 9
? = 1
? = ?+ 6?  + 9 − 5
?=?+ 6? + 4
? = 1 and ? = 6

✔ sub of turning point
(−3;5)
✔ sub of (0;4)
✔ simplification

(3)

     
8.3 Δ = ?− 4??
Δ = 36 − 4(1)(4)
Δ=20
????? ??? ?????????? ??? ???????

✔ Δ=20
✔ irrational
✔ unequal

(3)

     
8.4

?(?) = 2?
?+ 6? + 4 = 2?
?+ 4? + 4 = 0
(?+2)= 0
? = −2
?(−2)=−4

Point (−2;−4)

OR

?(?) = ?+ 6? + 4
?′(?) = 2? + 6 and ? = 2
2? + 6 = 2
2? = −4
? = −2
? = −4
Point (−2;−4)

✔ ?(?) = 2?
✔ equating equations
✔ ? = −2
✔ ? = −4

 

✔ derivative
?′(?) = 2? +6
✔ equating to gradient of g.
✔ x-value
✔ y-value

(4)
[11]

QUESTION 9   
 9.1

 ?(?) = 3?− 1
?′(?) = lim   ?(?+ℎ)−?(?)
          ℎ→0          ℎ
=    lim  3(? + ℎ)− 1 −(3?− 1)
     ℎ→0                      h
=   lim  3(?2 + 2xh + h2) − 1 - 3?− 1
     ℎ→0                      h
=   lim  3?2 + 6xh + 3h2− 1 - 3?− 1
     ℎ→0                      h
=       lim     6?ℎ
        ℎ→0      h
= 6?

 Answer only = 0 marks

Penalise 1 mark for incorrect use of formula. Must show ?′(?). 

✔ formula
✔substitution of (?+ℎ)
✔ simplification
3?+ 6?ℎ + 3ℎ− 1 − 3?+ 1
✔ =  lim     6?ℎ
        ℎ→0     h
✔ answer

(5)

     
 9.2.1  ? = 5?2 + √?
? = 5?+ ?½
??/?? = 10? + ½?−½

✔?½
✔10x
✔½?−½

(3)

     
 9.2.2  ?? [6?−4]
         3?
??[6?/3?−4/3?]
??[2 − 4/3?−1]
=−4/3?−2 or  4/3?2

✔ 2
✔ −4/3?−1
✔ answer

(3)

     
9.2.3 ? = ?′(?) =3?2
?2 ≥ 0
3?2 ≥ 0
∴ no value of t will make ?′(?) negative.

✔ derivative
✔ 3?≥ 0

(2)
[13]

QUSTION 10
10.1

?(?) = ?3 − ?2 − 8? + 12
(?−2)(?2 + ? − 6) = 0
(?−2)(?−2)(?+3) = 0
?=2 or ?=2 or ? = −3
?(−3;0)

OR

                         ?+3               
?− 4? + 4 √?− ?− 8? + 12
?− 4?2 +4?

     3?− 12? + 12
    3?− 12? + 12  
?(?) = (?− 4? + 4)(? + 3)
?(−3;0)

✔(?−2)
✔(?2 + ? − 6)
✔(?−2)(?−2)(?+3) 
✔coordinates of ? (−3;0)

 

 


✔?− 4? + 4
✔✔? + 3
✔coordinates of ? (−3;0)

(4)

     
10.2 ?′(?) = 3?− 2? − 8 = 0
(3? + 4)(? − 2) = 0
? = −4/3 or ? = 2
?(−4/3) = (−4/3)3 −(−4/3)− 8(−4/3) +12
B(−4/3; 500/27 )

✔?′(?) 
✔?′(?)  = 0
✔correct ? value ? = −4/3
✔y = 500/27 

(5)

     
10.3

 ?′′(?) = 6? − 2
6? − 2 = 0
? =1/3

OR

?=−4/3+2
        2
?=13

✔?′′(?) = 6? − 2
✔? =1/3
✔finding x value of  midpoint
✔? =1/3

(2)

     
 10.4  ? <−4/3 or  ? > 2

✔? <−4/3
✔? > 2

(2)

     
 10.5  ?=? ;?<0
Only one Real Root

 ✔answer

(2)
[15]

QUESTION 11
 11.1  ?(0) = 3 + ½(0)2 −14(0)3
?(0)=3 ?

✔?(0)=3 ?

(1)

     
 11.2  ?′(?) = ? − ¾?2
?′(3) =3 −¾(3)2
=3 − 27/4
=−15/4 m/h / m/u

✔?′(?)
✔?′(3)
✔=−15/4 or -3.75

(3)

     
 11.3  Decreasing

✔Decreasing

(1)

     
 11.4  ?′(? )= 0
?− ¾?= 0
4? − 3?= 0
?(4 − 3?) = 0
? = 0 or ? = 43
43 =1ℎ20???
Time: at 08h00 or 9h20 

✔?′(? )= 0
✔factors
✔t-values
✔answer

(4)
[9]

 

QUESTION 12

12.1 

12.1.1 

P(A′) = 1 − P(A) 
= 1 − 0,35 
= 0,65

✔ P(A′) = 1 − P(A) 
✔ answer

(2)

       
 

12.1.2 

P(AandB) = 0 
P(AenB) = 0

✔ answer

(1)

       
 

12.1.3 

P(A or B) = 0,35 + 0,52 
= 0,87

✔  P(A or B) = P(A) + P(B)
✔ answer

(2)

       

12.2 

12.2.1 

6! = 720 

✔ 6! or/of 720 

 (1)

       
 

12.2.2

4! 
= 24

✔4! 
✔ 24 

(2)

       
 

12.2.3

2!.5! =  240   = 1
  6!       720      3

OR 

0,333

✔ 2! 
✔ 5! 
✔ 6! 
✔ answer

(4) 
[12]

     

TOTAL: 150

Last modified on Tuesday, 15 June 2021 07:36