A curve has the equation y=x^2+4x+4 and a line has the equation y=2x+3. Show the line and curve have only one point of intersection and find its coordinate..

First set the equations equal to each other: x^2+4x+4 = 2x+3.Rearrange for x in form ax^2+bx+c : x^2+2x+1=0Factorise: (x+1)^2=0. Repeated root, hence only one intersection. x=-1. Using y=2x+3, y=1. So coordinate: (-1,1). Check answers by substituting values back into both equations. Note, I have chosen equations that can be easily factorised at every step so a graphical explanation could be easily conveyed.

EF

Related Maths GCSE answers

All answers ▸

A pizza has a radius of 12cm. Calculate the area of the pizza in cm² , giving your answer as a multiple of π.


Find and simplify the point(s) of intersection of the curves: x^2 + y^2 =6 , y = x - 3


Show that the two lines are parallel: L1: 4y = 24x +12, L2: 2y + 13 = 12x


Expand and simplify (3X+9)(X-6)=0