A dilation question

[fusion]

Hey would just like something cleared up

Say we have the equation f(X) = e^-x-1

and then it asks you to dilate by a factor of 1/3 from the y-axis

Is this e^3(-x-1) or just e^(-3x-1)

I think i've seen both somewhere while doing practise exams, thought insight 2008 has the answer as the second one.

Thanks

[shinny]

Using the general rules:

[bucket]

so does that mean dilating a graph alters any translations that have already been applied?

[riadnicolas]

so does that mean dilating a graph alters any translations that have already been applied?

im not sure but i think dilating then translating wont affect it, confirmation?

[Mao]

so does that mean dilating a graph alters any translations that have already been applied?

YES

which is why, dilations are often done before translations, and you see .

[sxcalexc]

so does that mean dilating a graph alters any translations that have already been applied?

YES

which is why, dilations are often done before translations, and you see .

But when you do translations after dilations they expect you to alter it anyway don't they? So (-x) goes to (-3x) after being dilated. Then to translate one across you go (-3(x-1)). So the bracket makes it 'up to date'?

Also, when they give you a list of transformations to apply, should you apply it in order? Does anyone have an example of such a question(s).

[Mao]

i don't quite understand your first question, but

ALWAYS do the given transformations in that order

[sxcalexc]

i don't quite understand your first question, but

ALWAYS do the given transformations in that order

Lol, umm.. Disregard the first one ... and thanks.

[fusion]

ok thanks

So just confirming say we start with E^X

It then says Dilate by a factor of 1/3 from y axis
Translate one unit to the right along the x-axis

You would dilate first, e^3x, and then the transformation which would make it e^3(x-1) ?

However if it said
Translate one unit to the right along the x-axis
Dilate by a factor of 1/3 from y axis

You would translate first, e^x-1, and then dilate to make it e^3x-1 ?

Is this right, Thanks again