Thread: Express the following equations in a form suitable for drawing a straight line graph

Express the following equations in a form suitable for drawing a straight line graph, stating its axes, gradient and vertical intercept.

1. y = e^(ax + by)
2. y = (a / b)^(xy + 1)

Assuming that a and b are unknown constants to be determined ?

For the first relationship, take logs

and then divide by (you could also divide by , that would lead to an alternative equation),



Then construct the new variables and

That will give you the straight line which has a slope of and an intercept of

You can do a similar thing with the second example.

For the second question, this is what I did:
lg y = (xy + 1)(lg a - lg b)
lg y = xy lg a - xy lg b + lg a - lg b
lg y = (lg a/b)xy + lg a/b

So the Y-axis = lg y, X-axis = xy, gradient = lg a/b and vertical intercept = lg a/b
Is this correct?

Yes, that should work.