Functions and Graphs Test Corrections

Test Corrections: Functions and Graphs

9a)
This graph was a parabola going through the points (2,1) (vertex), (-1, 3) and (5,3). If this graph had no stretch or shrink it would have had the two additional points at (1, 2) and (3,2), so I knew on the test that this had a stretch/shrink. At this point, I only eyeballed and estimated 1/2 was about right, but I was wrong. What I should have done was to algebraically calculate the stretch/shrink. I could do this by considering that on the parent graph, a point three away from the vertex would have a y-value of  3^2, or 9. This point, however, on this graph, was only 2 y-values up from the origin. Therefore it had a shrink of 2/9.

9f)
This graph was a translated graph of the parent graph 1/x. This graphs "vertices," for my lack of a better term, should go through the points (1,1) and (-1,-1) on the parent graph. On the graph on the test, however, the "vertices" go through no distinct point. This is how I knew there was a stretch/shrink. I therefore correctly put 2/x-1 as part of my answer. Where I went wrong was by adding a -1 to the end. I saw the graph as shifted down 1 because the portion that would normally be in the 3rd quadrant appeared to me at the time as having shifted down one. This was just my perception being deceived however, as I had already accounted for the shift in the graph in the x-1.

I found this unit to be pretty easy, but sometimes I got the discontinuities wrong. 

Summer Assignment Test

I got half a point off of problem number 3. Here is the problem redone:
       2/2x-5+3
       2/2x-2
       1/x-1
I also got number 6 wrong. Here is the problem redone:
       A. 13x-20y+40=0
            13x+40=20y
            13/20x+2=y wrong slope and right y-intercept
***answer I originally put because I only looked at the y-intercept***
      B.  3x+2y-1=0
           3x-1=-2y
            3/2x+1/2=y wrong slope and wrong y-intercept
      C.  4x-3y+6=0
            4x+6=3y
            4/3x+3=y right slope and right y-intercept
***correct answer***
      D.  6x-3y=0
            6x=3y
            2x=y wrong slope and wrong y-intercept

These are the only two problems that I got points off on. I found the test to be fairly easy because most of it was review from Algebra I and II.