Previous Back to Lab Intro Back to Tutorials

Tutorial: Euler's Method

We fill in the second row and copy down for our example y' = y – 2t, with initial condition y(1) = 5 using a step size of = 1 on the interval from 1 to 5.

Step 3: Row Two and Fill Down

Next we fill in y on the next row. We know that we should have y(2) is approximately y(1) + h y'(1). We will fill this in to row two column two using a formula based on row one, which contains values for y(1)_and y'(1). We use the formula =B2+1*C2 in cell B3. For the y' entry, we can copy the entry from row two, since we used a formula. This gives us the following in our table:

 
A
B
C
1
t values
y values y' values
2
1
5
3
3
2
8
4
4
3
5
4

Finally, since everything in the y and y' entries of row two is a formula, we can fill down (or drag down) the two entries in row two to the rest of our table. When Excel finishes calculating, we get the following:

 
A
B
C
1
t values
y values y' values
2
1
5
3
3
2
8
4
4
3
12
6
5
4
18
10
6
5
28
18

 

 

Previous Back to Lab Intro Back to Tutorials