You are not logged in.
Pages: 1
Please explain why! Thanks
I think the hardest bit I don't get is how to explain the dilations!
Last edited by Identity (2007-10-27 22:54:59)
Offline
You have x².
Firstly, enlarge the graph with scale factor 1/2 with the y axis as the line of enlargement.
(As in, move every point halfway between its current position and the y axis.) This makes it (2x)².
Second, translate the graph with vector (6,0). (Shift it 6 places to the right). This makes your graph (2x-6)².
Now enlarge the graph with scale factor -3 with the x axis as the line of enlargement to get -3(2x-6)².
Finally, translate it with vector (0,4) to get -3(2x-6)²+4.
Why did the vector cross the road?
It wanted to be normal.
Offline
I thought the x-coordinate should move by a vector (3,0), since we have (2(x-3))² ?
Offline
(3,0) is when translating y = x[sup]2[/sup], (6,0) is when translating y = (2x)[sup]2[/sup].
You could also rewrite equation of the new curve as
and save yourself one transformation in the process. (Namely, you only need three rather than four transformations: apply (3,0) translation, scale vertically by −12, and apply (0,4) translation.)
Offline
Okk, thanks Jane and mathsy, transformations is still pretty confusing to me, hope i did well on the test
Offline
Ok this was a question on the test:
Find the image of this graph after a dilation of 3 from the x axis, a reflection in the y axis, and finally a translation of 2 units in the positive direction of the y-axis.
I did this:
Let (x,y) map on to (x', y')
Then
So
Is that right?
I have a feeling it is wrong...
Last edited by Identity (2007-10-29 04:54:18)
Offline
Pages: 1