Gradient m = − 1 − 5 2 − ( − 3 ) = − 6 5 = − 1.2 m = \frac{-1 - 5}{2 - (-3)} = \frac{-6}{5} = -1.2 m = 2 − ( − 3 ) − 1 − 5 = 5 − 6 = − 1.2
Mark: 1 for substitution, 1 for final answer.
Distance d = ( − 1 − 4 ) 2 + ( 6 − ( − 2 ) ) 2 = ( − 5 ) 2 + 8 2 = 25 + 64 = 89 d = \sqrt{(-1 - 4)^2 + (6 - (-2))^2} = \sqrt{(-5)^2 + 8^2} = \sqrt{25 + 64} = \sqrt{89} d = ( − 1 − 4 ) 2 + ( 6 − ( − 2 ) ) 2 = ( − 5 ) 2 + 8 2 = 25 + 64 = 89
Mark: 1 for formula, 1 for 89 \sqrt{89} 89 .
Midpoint formula: 3 = 7 + x 2 ⇒ x = − 1 3 = \frac{7 + x}{2} \Rightarrow x = -1 3 = 2 7 + x ⇒ x = − 1 ; − 4 = 2 + y 2 ⇒ y = − 10 -4 = \frac{2 + y}{2} \Rightarrow y = -10 − 4 = 2 2 + y ⇒ y = − 10 . Point S ( − 1 , − 10 ) S(-1, -10) S ( − 1 , − 10 ) .
Mark: 1 for x-coord, 1 for y-coord.
y − ( − 1 ) = − 2 3 ( x − 6 ) ⇒ y + 1 = − 2 3 x + 4 ⇒ y = − 2 3 x + 3 y - (-1) = -\frac{2}{3}(x - 6) \Rightarrow y + 1 = -\frac{2}{3}x + 4 \Rightarrow y = -\frac{2}{3}x + 3 y − ( − 1 ) = − 3 2 ( x − 6 ) ⇒ y + 1 = − 3 2 x + 4 ⇒ y = − 3 2 x + 3
Mark: 1 for substitution, 1 for final equation.
Line 1: m = 6 − 2 3 − 1 = 2 m = \frac{6-2}{3-1} = 2 m = 3 − 1 6 − 2 = 2 . Line 2: m = 4 − 0 2 − 0 = 2 m = \frac{4-0}{2-0} = 2 m = 2 − 0 4 − 0 = 2 . Since gradients are equal, they are parallel.
Mark: 1 for both gradients, 1 for conclusion.
x = 2 ( 2 ) + 1 ( 8 ) 1 + 2 = 12 3 = 4 x = \frac{2(2) + 1(8)}{1+2} = \frac{12}{3} = 4 x = 1 + 2 2 ( 2 ) + 1 ( 8 ) = 3 12 = 4 ; y = 2 ( 10 ) + 1 ( − 2 ) 1 + 2 = 18 3 = 6 y = \frac{2(10) + 1(-2)}{1+2} = \frac{18}{3} = 6 y = 1 + 2 2 ( 10 ) + 1 ( − 2 ) = 3 18 = 6 . Point ( 4 , 6 ) (4, 6) ( 4 , 6 ) .
5 2 = ( k − 2 ) 2 + ( 3 − ( − 1 ) ) 2 ⇒ 25 = ( k − 2 ) 2 + 16 ⇒ ( k − 2 ) 2 = 9 ⇒ k − 2 = ± 3 5^2 = (k-2)^2 + (3 - (-1))^2 \Rightarrow 25 = (k-2)^2 + 16 \Rightarrow (k-2)^2 = 9 \Rightarrow k-2 = \pm 3 5 2 = ( k − 2 ) 2 + ( 3 − ( − 1 ) ) 2 ⇒ 25 = ( k − 2 ) 2 + 16 ⇒ ( k − 2 ) 2 = 9 ⇒ k − 2 = ± 3 . k = 5 k = 5 k = 5 or k = − 1 k = -1 k = − 1 .
Mark: 1 for equation, 2 for both values.
3 y = 2 x − 6 ⇒ y = 2 3 x − 2 3y = 2x - 6 \Rightarrow y = \frac{2}{3}x - 2 3 y = 2 x − 6 ⇒ y = 3 2 x − 2 . Gradient m = 2 3 m = \frac{2}{3} m = 3 2 .
Mark: 2 for correct gradient.
m 1 = 4 ⇒ m 2 = − 1 4 m_1 = 4 \Rightarrow m_2 = -\frac{1}{4} m 1 = 4 ⇒ m 2 = − 4 1 . y − 3 = − 1 4 ( x − 2 ) ⇒ y = − 1 4 x + 1 2 + 3 ⇒ y = − 1 4 x + 3.5 y - 3 = -\frac{1}{4}(x - 2) \Rightarrow y = -\frac{1}{4}x + \frac{1}{2} + 3 \Rightarrow y = -\frac{1}{4}x + 3.5 y − 3 = − 4 1 ( x − 2 ) ⇒ y = − 4 1 x + 2 1 + 3 ⇒ y = − 4 1 x + 3.5 .
Mark: 1 for m 2 m_2 m 2 , 2 for equation.
Midpoint of A B AB A B is M ( 2 , 0 ) M(2, 0) M ( 2 , 0 ) . Line C M CM C M passes through ( 2 , 6 ) (2, 6) ( 2 , 6 ) and ( 2 , 0 ) (2, 0) ( 2 , 0 ) . This is a vertical line x = 2 x = 2 x = 2 .
Mark: 1 for midpoint, 2 for equation.
L 2 : y − 4 = − 3 ( x − 0 ) ⇒ y = − 3 x + 4 L_2: y - 4 = -3(x - 0) \Rightarrow y = -3x + 4 L 2 : y − 4 = − 3 ( x − 0 ) ⇒ y = − 3 x + 4 . Intersection: − 3 x + 4 = x − 2 ⇒ 4 x = 6 ⇒ x = 1.5 -3x + 4 = x - 2 \Rightarrow 4x = 6 \Rightarrow x = 1.5 − 3 x + 4 = x − 2 ⇒ 4 x = 6 ⇒ x = 1.5 . y = 1.5 − 2 = − 0.5 y = 1.5 - 2 = -0.5 y = 1.5 − 2 = − 0.5 . Point ( 1.5 , − 0.5 ) (1.5, -0.5) ( 1.5 , − 0.5 ) .
Mark: 1 for L 2 L_2 L 2 , 2 for intersection.
m p o i n t s = 1 − 5 3 − 1 = − 2 m_{points} = \frac{1-5}{3-1} = -2 m p o in t s = 3 − 1 1 − 5 = − 2 . Perpendicular gradient m = − 1 − 2 = 0.5 m = \frac{-1}{-2} = 0.5 m = − 2 − 1 = 0.5 .
Mark: 1 for point gradient, 2 for m m m .
Vector A B = ( 3 , 1 ) AB = (3, 1) A B = ( 3 , 1 ) . Perpendicular vector B C = ( − 1 , 3 ) BC = (-1, 3) B C = ( − 1 , 3 ) . C = ( 4 − 1 , 2 + 3 ) = ( 3 , 5 ) C = (4-1, 2+3) = (3, 5) C = ( 4 − 1 , 2 + 3 ) = ( 3 , 5 ) . D = ( 1 − 1 , 1 + 3 ) = ( 0 , 4 ) D = (1-1, 1+3) = (0, 4) D = ( 1 − 1 , 1 + 3 ) = ( 0 , 4 ) .
Mark: 2 for C C C , 2 for D D D .
Vertex ( h , k ) = ( 3 , − 4 ) (h, k) = (3, -4) ( h , k ) = ( 3 , − 4 ) .
Mark: 2 for correct coordinates.
Set y = 0 ⇒ x + 1 = 0 y=0 \Rightarrow x+1=0 y = 0 ⇒ x + 1 = 0 or x − 5 = 0 x-5=0 x − 5 = 0 . Intercepts: ( − 1 , 0 ) (-1, 0) ( − 1 , 0 ) and ( 5 , 0 ) (5, 0) ( 5 , 0 ) .
Mark: 2 for both coordinates.
y = ( x 2 − 6 x + 9 ) − 9 + 5 ⇒ y = ( x − 3 ) 2 − 4 y = (x^2 - 6x + 9) - 9 + 5 \Rightarrow y = (x - 3)^2 - 4 y = ( x 2 − 6 x + 9 ) − 9 + 5 ⇒ y = ( x − 3 ) 2 − 4 .
Mark: 3 for correct completion of square.
1 = a ( 0 − ( − 2 ) ) 2 + 5 ⇒ 1 = 4 a + 5 ⇒ 4 a = − 4 ⇒ a = − 1 1 = a(0 - (-2))^2 + 5 \Rightarrow 1 = 4a + 5 \Rightarrow 4a = -4 \Rightarrow a = -1 1 = a ( 0 − ( − 2 ) ) 2 + 5 ⇒ 1 = 4 a + 5 ⇒ 4 a = − 4 ⇒ a = − 1 .
Mark: 1 for substitution, 2 for a a a .
Vertex: x = − ( − 4 ) / 2 = 2 , y = 4 − 8 − 5 = − 9 ⇒ ( 2 , − 9 ) x = -(-4)/2 = 2, y = 4-8-5 = -9 \Rightarrow (2, -9) x = − ( − 4 ) /2 = 2 , y = 4 − 8 − 5 = − 9 ⇒ ( 2 , − 9 ) . x-intercepts: ( x − 5 ) ( x + 1 ) = 0 ⇒ ( 5 , 0 ) , ( − 1 , 0 ) (x-5)(x+1)=0 \Rightarrow (5,0), (-1,0) ( x − 5 ) ( x + 1 ) = 0 ⇒ ( 5 , 0 ) , ( − 1 , 0 ) . y-intercept: ( 0 , − 5 ) (0, -5) ( 0 , − 5 ) .
Mark: 1 for vertex, 1 for x-ints, 1 for y-int, 1 for smooth curve.
y = ( x + 2 ) ( x − 4 ) = x 2 − 2 x − 8 y = (x+2)(x-4) = x^2 - 2x - 8 y = ( x + 2 ) ( x − 4 ) = x 2 − 2 x − 8 . Therefore b = − 2 , c = − 8 b = -2, c = -8 b = − 2 , c = − 8 .
Mark: 1 for expansion, 2 for b b b and c c c .
Translation of the graph of y = 2 x 2 y = 2x^2 y = 2 x 2 by the vector ( 1 3 ) \begin{pmatrix} 1 \\ 3 \end{pmatrix} ( 1 3 ) (1 unit right, 3 units up).
Mark: 1.5 for right, 1.5 for up.