For the equation x^2 - 2x - 8 = y find: (a) The roots. (b) The y-intercept. (c) The coordinate of the turning point

(a) Several methods to do this, simplest would be to factorise the quadratic into (x - 4)(x + 2) = 0 and from here see that root occur at x = 4 and x = -2.(b) Substitute x = 0 into the equation 0^2 - 20 - 8 = - 8 = y, so y-intercept at y = -8.(c) Quadratic equations are symmetrical so the x coordinate of the tuning point occurs midway between the 2 roots so x = 1, substitute this into the equation to get out y = 1^2 - 12 - 8 = -9, so the coordinate of the tuning point is (1,-9).

BC
Answered by Benjamin C. Maths tutor

4380 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

n is an integer such that 3n + 2 < 14 and 6n/(n^2+5) > 1. Find all possible values of n.


Solve the simultaneous equations 3x+2y=13 and 4x+y=14


Solve the simultaneous equations to find x and y: 3x + 5y = 10 , 5x + 4y = 8


Solve the simultaneous equations 3x +y =11 and 2x+y=8


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