Post by: fusion on November 06, 2008, 05:36:37 pm
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
Post by: shinny on November 06, 2008, 05:39:46 pm
Post by: bucket on November 06, 2008, 05:42:10 pm
Post by: riadnicolas on November 06, 2008, 05:46:04 pm
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?
Post by: Mao on November 06, 2008, 05:52:49 pm
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
Post by: sxcalexc on November 06, 2008, 05:58:28 pm
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'?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.
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).
Post by: Mao on November 06, 2008, 06:07:09 pm
ALWAYS do the given transformations in that order
Post by: sxcalexc on November 06, 2008, 06:14:18 pm
i don't quite understand your first question, butLol, umm.. Disregard the first one ... and thanks.
ALWAYS do the given transformations in that order
Post by: fusion on November 06, 2008, 08:04:51 pm
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