Presentation on theme: "Let's zoom in on one corner of the coordinate plane"— Presentation transcript:
1 Let's zoom in on one corner of the coordinate plane Let's zoom in on one corner of the coordinate plane. (This corner is called the first quadrant.)The point where the two axes cross has a special name: it is called the origin.The blue lines will help us find points. When you make your own graphs, you can use the lines on your graph paper to help you.(0,0)
2 Finding Points in the Plane We can find every point in the plane using two numbers. These numbers are called coordinates. We write a point's coordinates inside parentheses, separated by a comma, like this:(5, 6). Sometimes coordinates written this way are called an ordered pair.The first number in an ordered pair is called the x-coordinate. The x-coordinate tells us how far the point is along the x-axis.The second number is called the y-coordinate. The y-coordinate tells us how far the point is along the y-axis.
3 Estimating PointsSometimes, the point you want to graph is in between points that are marked on the axes. When this happens, you must estimate where to put your point.For example, graph(5, 13) using these axes:(5,13)
4 Some Rules for All Graphs All of your graphs should have…A titleAt the top of the graph and underlinedIt should represent what you are graphing (use your variables)
5 Some Rules for All Graphs con’t Labeled AxisUse a straight-edge to draw all linesUse the blue lines that are provided for you on the graph paper.Axes should be drawn a few lines in and up from the edge of the paperYou must state what is represented on the x-axis and what is represented on the y-axis; include units when necessary
6 Some Rules for All Graphs con’t The appropriate scaleWe need the graph to fill up the most paper. To find the right scale, we divide the range of the values by the number of tick marks on that axis. (Range is the highest value – the lowest value).Then we round to a number that is easy to count by.
7 How to Graph Hold the graph paper the tall way. Title it using the variables.Label the axes; don’t forget to include units.Draw axes a couple of lines up and overCount the number of lines going across the x-axis starting at the zero mark20 linesDistance vs. TimeDistance (m)Time (min)
8 Scale the x-axisTime (min)Distance (m)12345678910Find your range for the x-axis (in science it’s the highest data point because we always start from zero)Time: 10-0=10 so range is 10Divide the range of the x-axis by the # of lines on the x-axis: 10/20=0.50.5 is an easy-to-count by number so count EVERY blueline as 0.5
9 Scale the x-axis: Distance vs. Time Distance (m) Time (min)
10 Scale the y-axis Repeat for the y-axis: tic marks = 30 lines Time (min)Distance (m)1102403354505656707908859100110Scale the y-axisRepeat for the y-axis: tic marks = 30 linesRange = 110/30= so round to 5; Count the y-axis by 5sCould also count by 4s
11 Nice Counting Numbers Once in a while you might have to Whole Numbers:1251015202550100Etc.Decimals:0.10.20.250.5Once in a while you might have tocount by a different not so nice number!
12 Make Ordered Pairs (0,0) (1,10) (2,40) Plot data (3,35) (4,50) (5,65) Distance vs. Time(0,0)(1,10)(2,40)(3,35)(4,50)(5,65)(6,70)(7,90)(8,85)(9,100)(10,110)Plot data100908070605040302010Distance (m)Relationship: The average distanced traveled is fairly constant for each time period.Time (min)
13 Review: All Graphs need: A titleAt the top and underlinedLabeled AxesAxes scaled appropriately (every tick mark increases by the same amount; each axes can be scaled differently)
14 Some Graphs need:A Key (when necessary) If you are putting more than one line on a graph, it must have a key to distinguish the difference
15 Different Types of Graphs Tables, charts and graphs are convenient ways to clearly show your data.
16 There are three basic graph forms. Line GraphBar GraphCircle (or Pie) GraphNotice on the next few slides how each of the following examples are used to illustrate the data.Choose the best graph form to express your results.
17 Bar Graph A bar graph is used to show relationships between groups. The two items beingcompared do not needto affect each other.It's a fast way toshow big differences.Notice how easy it isto read a bar graph.
18 Circle Graph or Pie Graph A circle graph is used to show how a part of something relates to the whole.This kind of graph is needed to show percentages effectively.
19 Line GraphA line graph is used to show continuing data; how one thing is affected by another.It's clear to see how things are going by the rises and falls a line graph shows.
20 The same data displayed in 3 different types of graphs. Bar GraphLine GraphCircle (Pie) Graph
21 Choosing the Right Graph Use a bar graph if you are not looking for trends (or patterns) over time; and the items (or categories) are not parts of a whole.Use a pie chart if you need to compare different parts of a whole, there is no time involved and there are not too many items (or categories).Use a line graph if you need to see how a quantity has changed over time. Line graphs enable us to find trends (or patterns) over time.