Sec. 2-5: Absolute Value Functions & Graphs

The graph of an absolute value function will look like the letter “V”. The reason for this is because when you enter both positive & negative values in for the “x”, the y result will always be positive The key to graphing absolute value functions is to determine the VERTEX first. 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. Finally, pick x values on either side of the vertex, plug those values into your equation to find the y’s. GRAPH.

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 “X” value to get your points. x y V: 5/2 -3 L: 0 17 R: 3 1

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 V: 5 0 L: 4 -2 R: 6 -2 **If you pick numbers the same distance from your vertex you’ll get a “nice” V.

x y V: 5 0 L: 4 -2 R: 6 -2 Video Help