
2 Attachment(s)
Linear law question
The first attachment shows the question I need to ask. So, I've drawn the graph, but don't know how to do part b, which is to find a and b, the value of x when y=20x^2 and the volume of the cuboid. Also, for c, how to draw y=x^3, as in terms of the scale, it would reach quite a large number so how do I put I down?Thx

Re: Linear law question
Hey Thorpelizts.
For your graph recall that the gradient (which is your a) is given by the change in y over a change in x.
So since you have a straight line you can get this by looking at some interval (say between 1 and 2) and then look at the difference between in the y values for x = 1 and x = 2. Your a value (which is also called the gradient) will be (y2  y1)/(x2  x1) where y2 is the y value for x = x2 and y1 is the y value for x = x1.
Now for the b: b actually represents the yintercept.
If you have an equation y = mx + b and you let x = 0, you get y = b which is the value when the function crosses the yaxis (which is why this is called the yintercept).
So if you look at where the graph crosses the yaxis, this is your b value.

Re: Linear law question
What abt part c? About the scale?