How do I know when a quadratic function crosses the y-axis?

The key thing to remember here is that the y-axis is a straight line and all of the points that lie on it have the x-value of 0. This means that the curve crosses the y-axis when x=0 so you can substitute this into the function to calculate the y value.For example, if y = x2 + 6x + 8, we would substitute x with 0 to calculate y.y = x2 + 6x + 8y = 02 + 6(0) + 8y = 0 + 0 + 8 = 8Therefore the function crosses the y-axis when x is 0 and y is 8, the co-ordinate (0,8).

Answered by Scott R. Maths tutor

5110 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Derive the quadratic formula form the general quadratic equation


A cuboid has sides such that the longest side is two units more than the shortest side, and the middle length side is one unit longer than the shortest side. The total surface area of the cuboid is 52 units². What is the length of the shortest side?


When using trigonometry to calculate side lengths/angles, how do you know which identity to use?


Solve the simultaneous equations 5x + y = 21, and x - 3y = 9.


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 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences