Draw the graph y = x2 + 3x + 2

y = x2 + 3x + 2 Finding the y intercept:When x = 0, y = 2 Therefore y intercept is at (0,2)Finding x intercept:Method 1: Factorise y = x2 + 3x + 2 y = (x+1)(x+2)x intercepts are when y = 0 , therefore find values of x which make the bracket 0x = -1 and -2Therefore x intercepts are ( -1,0) and ( -2,0)Method 2: Completing the square0 = x2 + 3x + 2 0 = (x+3/2)2 -9/4 +20 = (x+3/2)2 -1/4Bring -1/4 to the other side (x+3/2)2 = 1/4Root both sidesx + 3/2 = +/- root( 1/4)x = -3/2 +/- root ( 1/4) Therefore roots at x = -1 or -2 Finding the minimum using completing the square:Once you have completed the square on the equation, the x coordinate of the minimum is the value of x which makes the bracket 0:0 = (x+3/2)2 -1/4X coordinate for minimum = -3/2The y coordinate for the minimum is the number out side of the brackets:Y coordinate for minimum = -1/4Therefore, coordinate for minimum = -3/2, -1/4

Answered by George R. Maths tutor

2947 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Factorise x^2 + 8x + 12 (2017 non-calculator paper)


Simplify the following, 125^-2/3


Factorise the expression: 8x + 32


Solve algebraically: 6a+b = 16 and 5a - 2b = 19


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