how do you know if two straight lines on a graph are parallel or perpendicular?

On a straight line graph, the lines are formed by an equation in the form y=mx + c. The m value in this equation represents the gradient, and the c value is the y-intersect.If two lines are parallel, this means that they have the same gradient, and so if the m values are the same, the lines will be parallel. For example, y=3x+2 and y=3x-1 are parallel. They are the same line, just translated down three on the y-axis.For two lines to be perpendicular their gradients (the m values) must multiply to make -1. For example the product of 4 and -1/4 is -1, and so the two lines y=4x-6 and y=3-1/4x will be perpendicular.

Answered by Annie T. Maths tutor

2592 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Find the volume of a right angled triangular prism with an angle of 28 degrees, hypotenuse of length 10 cm, and projected length of 12.5 cm. Give your answer in cm^3, to three significant figures.


The point P has coordinates (3, 4) The point Q has coordinates (a, b) A line perpendicular to PQ is given by the equation 3x + 2y = 7 Find an expression for b in terms of a.


Solve x^2 - 7x > -6


How to do Indices?


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2024

Terms & Conditions|Privacy Policy
Cookie Preferences