Unit 1
6 marks · HardConsider the expression .
Given the set S = {}.
A point A has coordinates (1, 1) and is reflected in the x-axis.
Simplify the expression as much as possible.
List all the elements of set S in their lowest terms.
Write the coordinates of the image of point A after the reflection.
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.
Show answer
(a) −2x + 7y
(b)
(c) (1, −1)
Show mark scheme and worked solution
Marking points
M1 (a) · 1 mark · Groups and collects like terms correctly.
A1 (a) · 1 mark · Gives the correct simplified answer (−2x + 7y or equivalent).
M2 (b) · 1 mark · Identifies how to simplify each fraction in S.
A2 (b) · 1 mark · States all fractions correctly simplified.
M3 (c) · 1 mark · Reflects the y-coordinate only.
A3 (c) · 1 mark · Gives (1, -1) as the image's coordinates.
Worked solution
(a) Group like terms: x - 3x = -2x, 2y + 5y = 7y. The answer: −2x + 7y.
(b) , , is already in simplest form.
(c) Reflecting in the x-axis changes the sign of the y-coordinate. The image is (1, −1).