Sec. 2-5: Absolute Value Functions & Graphs 10/13/17 Notebook Quiz Monday!
However, if we determine the VERTEX first, graphing will be easier. The graph of an absolute value function will look like the letter “V”. Graphing can be done by picking values for “x”, and finding the corresponding values for “y”. However, if we determine the VERTEX first, graphing will be easier. Do this by setting what’s INSIDE the absolute value equal to zero…this will give you the x-value of the vertex. Put that number back into the original equation to get the y-value.
Graph y = 4|2x – 5| – 3 Set the 2x – 5 = 0 to find x = 5/2, then put the 5/2 back into the equation to see what “y” is. Once you know the VERTEX, pick x-values to the left & right of the vertex to get your points. x y Vertex: 5/2 -3 Left: 0 17 Right: 3 1 Hmm there was a “– 3” in the original… What number in the original equation makes this “V” so narrow?.... The 4
Get your vertex: 5 – x = 0… so x is 5. Try this one! y = -2|5 – x| Get your vertex: 5 – x = 0… so x is 5. Put 5 back in to find “y”: y = 0 so V: (5, 0) x y Vertex: 5 0 Left: 4 -2 Right: 6 -2 **If you pick numbers the same distance from your vertex you’ll get a ‘nice’ graph. + 0 Hmm there was a 0 in the original. See it?
x y V: 5 0 L: 4 -2 R: 6 -2 I didn’t actually put 6 in for x. I knew that y had to be -2 when x = 6. How?? I know when x = 4, y = -2. x = 4 is one unit to the left of the vertex. x = 6 is one unit to the right, and since it’s absolute value, the y-value will be the same. I.E. The left side of the “V” is a mirror image of the right.
Assignments can be turned in late (for only 2 out of 5 points however). After 5 school days I CAN NOT ACCEPT LATE WORK (unless you were legally absent for several days). It is the student’s responsibility to make up all work, quizzes, and tests after a legal absence. Missed quizzes/tests must be made up immediately/ASAP. After 2 weeks have passed since the original date of the quiz/test a score of “0” will be entered.
Pg 88 #1 – 11 odd