TECHNICAL MATHEMATICS PAPER 2
GRADE 12
NATIONAL SENIOR CERTIFICATE
MEMORANDUM
JUNE 2018
NOTE:
Symbol | Explanation |
M | Method |
MA | Method with accuracy |
A | Accuracy |
CA | Consistent accuracy |
S | Simplification or Statement |
R | Reason |
SR | Statement and correct reason |
QUESTION 1
1.1 | BC =√( x2 - x1)2 + (y2 - y1)2 | MA formula ✓ substitution ✓ CA Answer ✓ (3) |
1.2 | A x-coordinate✓ A y-coordinate✓ (2) | |
1.3 | mBC = y2 - y1 | MA formula and substitution ✓ CA Simplification ✓ (2) |
1.4 | y - y1 = m ( x - x1 ) | M Correct formula✓ A Correct substitution pt D or E ✓ CA Simplification ✓ CA Standard form ✓ (4) |
1.5 | inclination of DE = inclination of BC (lines; same gradient) mDE = mBC AED = 111,8° - 36,87° | M mDE = mBC ✓ A tan incl DE = 0, 75 ✓ CA incl DE = 36,87° ✓ MA mAE =- 5✓ CA incl AE = 111,8°✓ CA AED = 74,93°✓ (6) |
[17] |
QUESTION 2 | ||
2.1.1 | r2 = x2 + y2 | M Correct formula✓ A Correct substitution✓ CA Value of r2✓ (3) |
2.1.2 | mradius = 0 +12 = 12 OR mradius = 0 +12 = 12 OR x1 x + y1 y = r 2 | MA Gradient of radius✓ CA Gradient of tangent✓ A Subst. P into equation✓ CA Equation of line✓
CA Gradient of tangent✓ MA Gradient of radius✓ CA Gradient of tangent✓ A Subst. P into equation✓
M Correct formula✓ A Correct substitution of P✓ A Correct substitution of grad.✓ CA Equation of line✓ (4) |
2.2 | 4x2 + 9 y2 = 36 x 2 + y 2 =1 | M Rewrite the equation RHS = 1✓ M Rewrite into a2 & b2✓ CA x-intercepts✓ CA y-intercepts✓ CA shape – clearly showing the horizontal major axis✓ (5) |
[12] |
QUESTION 3 | ||
3.1 | ||
3.1.1 | 13sinθ = 12 | M sin θ the subject✓ M Pythagoras✓ A x-value✓ A y-value✓ (4) |
3.1.2 | tanθ + secθ = 12 + 13 | CA correct value: tan✓ CA correct value: sec✓ CA answer✓ (3) |
3.1.3 | sinθ = 12 | M 180° -✓ CA 112,6°✓ (2) |
3.2 |
| A - tanq✓ A cos θ✓ A (-cosq )2✓ A (-sinq )2✓ A sinθ✓ A cos2 θ +sin2 θ =1✓ CA -sinθ✓ (7) |
3.3 | RHS = 2 | A RHS✓ A denominator✓ A numerator✓ A cos2 a +sin2 a =1✓ CA expansion✓ CA factorising✓ (6) |
[22] |
QUESTION 4 | ||
4.1 | sinθ = 9, 48 = 0, 606... | A trig ratio✓ CA value for θ ✓ (2) |
4.2 | Area Δ PSR = ½ PS´SQ sin PSˆQ | A area-rule✓ CA value for PSˆQ✓ A correct substitution✓ CA Area of ∆DEF✓ (4) |
4.3 | PSˆQ = 90°- 37,31° = 52, 69° | S ✓ A cos-rule✓ A correct substitution✓ CA simplification✓ CA value of✓ (5) |
| [11] |
QUESTION 5 | ||
5.1. | A x-int’s 120° and 300°✓ A TP (30°;1)✓ A TP (210°;-1)✓ A shape✓ (4) | |
5.2.1 | Amplitude of f = 2 | A ✓ amplitude = 2 (1) |
5.2.2 | Range g: –1 ≤ y ≤ 1 | A y- values✓ CA interval✓ (2) |
5.2.3 | x = 90° | CA ✓ (1) |
5.2.4 | f (x) ≤ g(x) ⇔ x Î[210°;360°] OR 210° ≤ x £≤ 360° | CA x = 210°✓ CA x = 360°✓ A notation✓ (3) |
[11] |
QUESTION 6 | ||
6.1 | Proportionally(1) | |
6.2 | ||
Let QS = x | S SC = 4 – x ✓ S R ✓ S SA = x + 2 ✓ A Setup equation ✓ CA Simplify equation✓ CA value✓ (7)
| |
[8] |
QUESTION 7 | ||
7.1 | ||
7.1.1 | AB = 8,36 cm (sides opp = ∠ s) | S R ✓✓ S ✓ (3) |
7.1.2 | AB = 8, 36 ≈ 1, 41 BC = 8, 36 ≈ 1, 41 AC = 11,82 ≈ 1, 41 | S ✓ S ✓ S ✓ (3) |
7.1.3 | triangles are similar | S similar triangles ✓ (1) |
7.2 | ||
7.2.1(a) | Rˆ3 = Tˆ2 = 56° (∠s in same segment) | S R(2) ✓✓ |
7.2.1(b) | Rˆ4 = T1 = 56° (tan-chord) | S R ✓✓ (2) |
7.2.2 | Aˆ = Mˆ (∠s in same segment) | S ✓ S ✓ (2) |
7.2.3 | AP = PR (Δ s /// ) 8, 29 = 11,11 MP = 8, 29 x 3, 72 | S ✓ S ✓ S PT = 12,01 – 8,29 = 3,72 ✓ S ✓ S value of ✓ (5) |
[18] |
QUESTION 8 | ||
8.1 | ||
PTˆR = 90° (line from centre to midpt of chord) = 9, 472 - 8, 432 = 18, 616 TR = 4, 31... WR ≈ 8, 63 units | S ✓ R ✓ S Pythagoras ✓ A Simplification✓ CA Value of TR✓ CA Value of WR✓ (6) | |
8.2 | ||
ABO = 40° (radii; equal ∠ s opp equal sides) | S ✓ S ✓ S ✓ R ✓ S ✓ R ✓ (6) | |
[12] |
QUESTION 9 | ||
9.1.1 | 108, 5° = 108, 5° x π | A Multiply with factor✓ CA Answer✓ (2) |
9.1.2 | Radius = 10,84 = 5, 42 units | A Answer✓ (1) |
9.1.3 | s = rθ | A correct✓ CA ✓ Substitution CA answer ✓ (3) |
9.1.4 | Area =r 2 θ | A Correct formula✓ CA Substitution✓ CA answer✓ (3) |
9.2 | 4h2 - 4dh + x2 = 0 | A Correct formula✓ A Making d the subject✓ A Substitution✓ CA answer✓ (4) |
9.3 | ||
A Correct formula✓ A Convert to cm ✓ A Substitution✓ CA 109,8✓ CA 658,8✓ (5) | ||
18] |
QUESTION 10 | ||
10.1.1 | n = 15 rev/s | A Correct formula ✓ A Substitution✓ CA value of✓ (3) |
10.1.2 | d = 570mm = 0, 57m | A Convert diameter to metre✓ A Correct formula✓ A Substitution✓ CA value of v✓ (4) |
10.1.3 | s=vt | A Correct formula✓ A Multiply t = 2, with 60✓ CA value of s✓ CA rounded answer✓ (4) |
10.1.4 | θ = ωt | A Correct formula✓ Substitution✓ CA value of θ✓ (3) |
10.2 | Vol of cylinder = πr2h | A Formula of cylinder ✓ A Divide diameter by 2✓ A Substitution✓ CA Vol of cylinder✓ A Formula of hemisphere✓ A Substitution ✓ CA Vol of hemisphere✓ CA Adding the volumes✓ (7) |
[21] |
TOTAL;150