Unit 1
5 marks · NormalOn a graph, point P has coordinates ().
Let set S = {positive even numbers less than 10}.
Write down the coordinates of P after reflecting it in the y-axis.
List all elements of set S.
Point Q is (3, 1). Find the gradient of the straight line joining P to Q.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
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(a) (2, 1)
(b) {2, 4, 6, 8}
(c) 0
Show mark scheme and worked solution
Marking points
A1 (a) · 1 mark · Correct reflected coordinates (2,1)
B1 (b) · 2 marks · Correct listing of even numbers less than 10
A2 (c) · 2 marks · Correct gradient: (1-1)/(3+2)=0/5=0
Worked solution
a) Reflection in y-axis: x-coordinate changes sign; (2, 1).
b) Set S is {2, 4, 6, 8}.
c) Gradient = (y_2 - y_1)/(x_2 - x_1) = (1-1)/(3-(-2)) = 0/5 = 0.