What Picture is This?
- A B Cron
Student Objectives The student will graph and write equations of lines given characteristics such as two points, a point and a slope, or a slope and y - intercept. Materials - Each student should have the picture of the Kite and a graphing calculator or access to GeoGebra graphing grid like this one. Handout Procedures - Students may work in pairs and use a graphing calculator to complete this assignment. Given the picture of the kite, students will write the equations including the restrictions on the domain. Students will then create a program in their calculators to execute their equations. If they have correctly derived the equations, their calculators will draw the kite. GeoGebra Procedures For equation such as y = -(4/5)x + 9.4, -7< x<-2, type Function[-(4/5)x + 9.4,-7, -2] For vertical lines (equation such as x = -7, 3 < y < 15), type Segment[(-7, 3), (-7, 15)] Press Play to see the Kite Construction. GGT
TI-8# Calculator instructions: Go to program PRGM Go to Create New and hit Enter At the colon, type KITE and hit Enter To set the window for this drawing: type -15 and hit the STO key then go to VARS Window Ymin and hit Enter complete this process for Ymax, Xmin, Xmax, and set Xscl and Yscl to 5, making sure that each new command starts on a new line in the program with a colon. Add Zoom #5. At a new colon line: go to second program (Draw) and choose #6 DrawF (this means draw function) and hit enter. In the program immediately after the “DrawF command” type the equation ex. The first equation should be DrawF -(4/5)x + 9.4 /((x<-7)(x>-2)) or DrawF -(4/5)x + 9.4 /(-7<x and x> -2) notice no y = in the command and be very careful of the divide signs and parentheses. To draw a vertical line (these are not functions so the DrawF command can't be used.) Go to second program (Draw) menu and choose the Line command. Program line will look like this: Line (-7, 3, -7, 15) notice one set of parentheses and only commas separating the beginning and ending coordinate points. Exploration What did students find to be the most common error? Why does the calculator only draw part of the line? (Boolean Logic) Summary: This is a fun exercise that requires students to recognize the effect of the domain on the range. It is an alternative to regular rote and drill problems. Note, adding at beginning will improve the look of the output on the calculator screen FnOff–VARS Y-VARS #4 #2 PlotsOff–2nd STATPLOT #4 ClrDraw–2nd Draw #1