equation of a graph
Bruce is given the graph of y = 3x - 2
He is going to draw a second graph on the same axes.
He wants the x-coordinates of the points of intersection of the two graphs to be the solutions to the quadratic equation x^2 + x - 7 = 0
Work out the equation of the graph that needs to be drawn. Do not draw the graph.
I have tried a few ways of doing this -not sure if I am right!
x^2 + x -7 = 3x - 2 and solved, but soon realised that this gave me the x-cocordinates but not the 'equation of the graph that needs to be drawn'.
adding the two equations and trying to solve as a pair of simultaneous equations -didn't get very far that way either.
I'm a bit stumped, I'm not sure how I would go about tackling this kind of problem -help!
I'm not sure what you mean by 're-arrange this' , is it this?:
Originally Posted by mr fantastic
I can't see how this would work.
ooh, ooh, I think I got it....
I get c = -9 ....
Originally Posted by GAdams