Skip to main content

Back to the full dot-point answer

SingaporeAdditional MathematicsQuick questions

Coordinate Geometry and Circles

Quick questions on Parallel and perpendicular lines: N(A)-Level Additional Mathematics

8short Q&A pairs drawn directly from our worked dot-point answer. For full context and worked exam questions, read the parent dot-point page.

What are parallel lines?
Show answer
Two lines are parallel exactly when they have the same gradient:
What are perpendicular lines?
Show answer
Two lines are perpendicular (meet at a right angle) exactly when the product of their gradients is −1-1:
What is reading the gradient from an equation?
Show answer
If a line is given as y=mx+cy = mx + c, the gradient is the number mm in front of xx. If it is given as ax+by+c=0ax + by + c = 0, rearrange into y=mx+cy = mx + c first to read the gradient. Always extract the gradient cleanly before applying the parallel or perpendicular condition.
What is not rearranging first?
Show answer
If the line is 2x+y=52x + y = 5, rearrange to y=−2x+5y = -2x + 5 before reading the gradient as −2-2.
What are reciprocal slip with whole numbers?
Show answer
The negative reciprocal of 22 is −12-\tfrac{1}{2}; of 13\tfrac{1}{3} is −3-3.
What is q1?
Show answer
Write down the gradient of any line parallel to y=−4x+7y = -4x + 7. [1 mark]
What is q2?
Show answer
Find the gradient of a line perpendicular to one with gradient 35\dfrac{3}{5}. [1 mark]
What is q3?
Show answer
Find the equation of the line through (0,1)(0, 1) perpendicular to y=2x+3y = 2x + 3. [3 marks]

All Additional MathematicsQ&A pages