and

y = 4/x scales in the y-direction

are the "correct" answers shown in my a-level book. I don't see why they switch between y and x axis?]]>

The fact that you can also rotate the curve to get -1/x is a sidenote.]]>

With a curve of y=1/x, it gets scaled in both directions when the integer(1) there changes?]]>

So, to multiply all the x co-ordinates in y=x:sup2 by 2, you would have to change it to y=(x/2):sup2 = x:sup2/4.

And changing y = 1/x *does* scale it in the y direction, it just happens to scale in in the x direction as well because of symmetry.

y=4/x

I know that on a graph of y=x² you can put y=x²+z and the curve will be moved along the y axis by z. y = (x+z)² will move it along the x axis by z (but with a reversed sign). Similarly y=2x² will double each y co-ordinate;

Also, back to my original question on the curve of y = 1/x, if y = -1/x rotates the curve in the x-axis, why is y = 4/x supposedly scaling in the y-direction?

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