Posted by Melinda on .
Can someone help me with this question? I got the transformation for horizontal shift and vertical shift, however, I don't know how to find the vertical/horizontal compression/stretch.
1. Describe the transformations that were applied to the parent function to create the graph shown below. Then write the equation of the transformed function.
Parent function y=x^4
Here is the link to graph:
imgur dot com/Gkaln
I looked your graph and the new vertex is (-1,4)
so y = x^4 must have been translated to
y = (x+1)^4 + 4
but there could also be a compression , so let the new curve be
y = a(x+1)^4 + 4
from the graph we can see that (0,1) lies on the new curve
1 = a(1^4) + 4
-3 - a
so we have y = -3(x+1)^4 + 4
test for the other point shown
let x = -2
y = -3(-1)^4 + 4
all looks good
8th line should have said
-3 = a
(but you probably guessed that was a typo)
So it is a vertical stretch by -3?
How did you find out what a is if you knew it was UP 4, left 1?
Yes, the maginitude of the stretch is 3,
the - tells me the curve is opening downwards
I knew since the vertex was (-1,4)
and the parent graph of y = x^4 has a vertex at (0,0)
the graph must have moved 1 unit to the left and 4 units up
so we would get
y-4 = (x+1)^4
moving the -4 to the right made it +4
but y = (x+1)^4 + 4
would not pass through (0,1) as your picture shows.
so there must have been a stretch/compression.
that would be caused by some number in front of
so that is why I chose y = a(x+1)^4 + 4
subbing in the point (0,1) gave me a value of
a = -3