I don't understand how to do these can someone please help I have to understand by 2moro morning :(
-
This is a fun process. :)
1.) Create a table of values to use. Pick some easy numbers for "x" like -1, 0, and 1.
2.) For each x-value, plug it into the equation, and solve for y.
For example, I will use x = -1 to show you. Plug -1 as "x" into the equation "y = 2x + 1."
y = 2(-1) + 1
y = -2 + 1
y = -1
So for x = -1, your y = -1. Your ordered pair there would be (-1, -1). Now try that with all of the other numbers. In reality, since your equation is of a straight line, you simply need two numbers.
So let's try it with x = 0.
y = 2(0) + 1
y = 0 + 1
y = 1
So for x = 0, your y = 1. So your ordered pair there is (0, 1).
Now plot (-1, -1) and (0, 1) on your graph, and connect the points in a long, straight line. There is your graph! :)
1.) Create a table of values to use. Pick some easy numbers for "x" like -1, 0, and 1.
2.) For each x-value, plug it into the equation, and solve for y.
For example, I will use x = -1 to show you. Plug -1 as "x" into the equation "y = 2x + 1."
y = 2(-1) + 1
y = -2 + 1
y = -1
So for x = -1, your y = -1. Your ordered pair there would be (-1, -1). Now try that with all of the other numbers. In reality, since your equation is of a straight line, you simply need two numbers.
So let's try it with x = 0.
y = 2(0) + 1
y = 0 + 1
y = 1
So for x = 0, your y = 1. So your ordered pair there is (0, 1).
Now plot (-1, -1) and (0, 1) on your graph, and connect the points in a long, straight line. There is your graph! :)
-
Well, I can't really show you since I have no grid, but remember the y = mx + b model. The +1 at the end (which is not necessarily always at the end, but basically any constant that is not being multiplied by x) is the y-intercept, or where the line will cross the vertical axis. And the 2 in front of the x is your slope, which is rise / run or Δy / Δx, and since it's just 2, that means it's 2 / 1. That means that for every time x increases by 1 (Δx), y will increase by 2 (Δy).
So basically, to draw the graph, you'll want to start with your y-intercept, so you put a dot at (0,1), then go up 2 and over 1 and put another dot, and repeat, then draw your line through the dots.
Just for another example to help you understand, look at this graph: http://jwilson.coe.uga.edu/emt668/emt668…
The graph crosses the y-axis at (0,3), so you know there will be a +3 at the end, and the next dot goes up 2 and over 3, so the slope will be 2/3. The equation would be y = (2/3)x + 3.
So basically, to draw the graph, you'll want to start with your y-intercept, so you put a dot at (0,1), then go up 2 and over 1 and put another dot, and repeat, then draw your line through the dots.
Just for another example to help you understand, look at this graph: http://jwilson.coe.uga.edu/emt668/emt668…
The graph crosses the y-axis at (0,3), so you know there will be a +3 at the end, and the next dot goes up 2 and over 3, so the slope will be 2/3. The equation would be y = (2/3)x + 3.