Let's practice Euler's Method using a few concrete examples.
+
Using Euler's Method 1
@@ -1407,13 +1408,9 @@
.
- Using Euler's method, we find the approximate y(2) \approx -0.75.
-
-
- To help visualize the Euler's method approximation, these three points
- (connected by line segments)
- are plotted along with the analytical solution to the initial value problem in .
+ Using Euler's method, we find the approximation y(2) \approx -0.75.
+
Euler's Method approximation to \yp = x + y with y(1) = -1 from ,
along with the analytical solution to the initial value problem
@@ -1452,6 +1449,12 @@
+
+
+ To help visualize the Euler's method approximation, these three points
+ (connected by line segments)
+ are plotted along with the analytical solution to the initial value problem in .
+
@@ -1498,7 +1501,7 @@
along with the points from and the analytic solution,
are plotted in .
-
+
Euler's Method approximations to \yp = x + y with y(1) = -1 from Examples
and , along with the analytical solution
@@ -1642,7 +1645,7 @@
are plotted in .
Notice how well they seem to match the true solution.
-
+
Euler's Method approximation to \yp = y(1-y) with y(0) = 0.25 from ,
along with the analytical solution
Video examples for difference quotients: once with direct computation, and then by simplifying first
diff --git a/ptx/sec_limit_onesided.ptx b/ptx/sec_limit_onesided.ptx
index 2f794a779..d1f0980a5 100644
--- a/ptx/sec_limit_onesided.ptx
+++ b/ptx/sec_limit_onesided.ptx
@@ -741,7 +741,7 @@
It is also clearly stated that f(1) = 1.
-
+ Video solution
diff --git a/ptx/sec_lines.ptx b/ptx/sec_lines.ptx
index 5f11d533a..de47c395a 100644
--- a/ptx/sec_lines.ptx
+++ b/ptx/sec_lines.ptx
@@ -706,7 +706,7 @@
Therefore, we conclude that the lines \ell_1 and \ell_2 are skew.
-
+ Video solution
@@ -939,7 +939,7 @@
.
-
+
Determining distance from a line to a point
diff --git a/ptx/sec_par_calc.ptx b/ptx/sec_par_calc.ptx
index e080451ee..8461bdf54 100644
--- a/ptx/sec_par_calc.ptx
+++ b/ptx/sec_par_calc.ptx
@@ -500,7 +500,7 @@
therefore the tangent line is y=0, the x-axis.
-
+ Video solution
@@ -1108,10 +1108,10 @@
Increasing n shows that this value is stable and a good approximation of the actual value.
-
+
diff --git a/ptx/sec_param_eqs.ptx b/ptx/sec_param_eqs.ptx
index a4f211604..8074f793f 100644
--- a/ptx/sec_param_eqs.ptx
+++ b/ptx/sec_param_eqs.ptx
@@ -1038,7 +1038,7 @@
the graph defined by y=1-x with unrestricted domain is given in a thin line.
-
+ Video solution
@@ -1110,7 +1110,7 @@
demonstrating that the graph is indeed of an ellipse with a horizontal major axis and center at (3,1).
-
+ Video solution
@@ -1576,7 +1576,7 @@
-
+ Video solution
diff --git a/ptx/sec_partial_fraction.ptx b/ptx/sec_partial_fraction.ptx
index ad58d32f6..08d6d20a5 100644
--- a/ptx/sec_partial_fraction.ptx
+++ b/ptx/sec_partial_fraction.ptx
@@ -86,15 +86,17 @@
-
+
+
+
To find the coefficients A_i,
B_i and C_i:
diff --git a/ptx/sec_planes.ptx b/ptx/sec_planes.ptx
index a7d1e2a54..82578d290 100644
--- a/ptx/sec_planes.ptx
+++ b/ptx/sec_planes.ptx
@@ -301,7 +301,7 @@
-
+ Video solution
@@ -530,7 +530,7 @@
-
+ Video solution
@@ -795,7 +795,7 @@
-
+ Video solution
diff --git a/ptx/sec_polar.ptx b/ptx/sec_polar.ptx
index affb0ac54..9c6e8f454 100644
--- a/ptx/sec_polar.ptx
+++ b/ptx/sec_polar.ptx
@@ -783,7 +783,7 @@
-
+ Video solution
@@ -2008,7 +2008,7 @@
- We start by setting the two functions equal to each other and solving for \theta:
+ To start we set the functions equal to each other and solve for \theta:
1+3\cos(\theta) \amp = \cos(\theta)2\cos(\theta) \amp = -1
@@ -2019,7 +2019,7 @@
(There are, of course,
- infinite solutions to the equation \cos(\theta) =-1/2;
+ infinitely many solutions to the equation \cos(\theta) =-1/2;
as the limaçon is traced out once on [0,2\pi],
we restrict our solutions to this interval.)
-
+ Video solution
@@ -601,7 +601,7 @@
We did this example to demonstrate that the area formula is correct.
-
+ Video solution
@@ -1169,7 +1169,7 @@
which is accurate to 4 places after the decimal.)
-
+ Video solution
diff --git a/ptx/sec_ratio_root_tests.ptx b/ptx/sec_ratio_root_tests.ptx
index 449d031f3..4c542b3a4 100644
--- a/ptx/sec_ratio_root_tests.ptx
+++ b/ptx/sec_ratio_root_tests.ptx
@@ -308,7 +308,7 @@
-
+
diff --git a/ptx/sec_series.ptx b/ptx/sec_series.ptx
index bba19d7cc..b4b4a0316 100644
--- a/ptx/sec_series.ptx
+++ b/ptx/sec_series.ptx
@@ -718,7 +718,7 @@
-
+ Video solution
diff --git a/ptx/sec_space_coord.ptx b/ptx/sec_space_coord.ptx
index 93eb2cd27..f77920f3c 100644
--- a/ptx/sec_space_coord.ptx
+++ b/ptx/sec_space_coord.ptx
@@ -746,7 +746,7 @@
-
+ Video solution
diff --git a/ptx/sec_stokes_divergence.ptx b/ptx/sec_stokes_divergence.ptx
index 873a934a5..802410e0e 100644
--- a/ptx/sec_stokes_divergence.ptx
+++ b/ptx/sec_stokes_divergence.ptx
@@ -685,6 +685,9 @@
one has power to select the easiest computation as illustrated next.
+
+
+
Using the Divergence Theorem to compute flux
@@ -705,8 +708,6 @@
.
-
-
The direct flux computation requires six surface integrals,
one for each face of the cube.
diff --git a/ptx/sec_tan_norm.ptx b/ptx/sec_tan_norm.ptx
index 6f2293ae0..098580294 100644
--- a/ptx/sec_tan_norm.ptx
+++ b/ptx/sec_tan_norm.ptx
@@ -140,7 +140,7 @@
\unittangent(1) to verify it has length 1.
-
+ Video solution
@@ -229,7 +229,7 @@
-
+ Video solution
@@ -441,7 +441,7 @@
-
+ Video solution
@@ -846,7 +846,7 @@
Here the particle's speed is not changing and all acceleration is in the form of direction change.
-
+ Video solution
diff --git a/ptx/sec_taylor_poly.ptx b/ptx/sec_taylor_poly.ptx
index 2be67c0e3..035a6e9aa 100644
--- a/ptx/sec_taylor_poly.ptx
+++ b/ptx/sec_taylor_poly.ptx
@@ -223,7 +223,67 @@
whose first four derivatives at 0 match those of f.
-
+
+
Plotting f, p_2 and p_4
+
+
+ The graph of a function and two polynomials that approximate the function near x=0.
+
+
+ The graph of a function f(x) is shown. It is the same function as the first image in this section,
+ but again, the precise details of the graph are unimportant.
+
+
+
+ Also shown are the graphs of two functions p_2(x) and p_4(x).
+ The function p_2(x) is quadratic, and its graph is a parabola that opens upward.
+ The function p_4(x) is a polynomial of degree 4.
+
+
+
+ All three graphs intersect at the point (0,f(0)),
+ and the values of both p_2(x) and p_4(x) are close to the value of f(x) when x is close to 0.
+ Two observations are important: first, both of these polynomial graphs appear to lie more closely to the graph of f(x)
+ than the tangent line in the first image. Second, the graph of p_4(x) is a good approximation to f(x)
+ over a larger interval than the graph of p_2(x).
+
+
+
+ In particular, the point (0,f(0)) appears to be a local minimum,
+ and there is a corresponding minimum in the graphs of both p_2(x) and p_4(x).
+ But the graph of f(x) also appears to have a local maximum near x=1.
+ Near x=1, the graph of p_2(x) separates from that of f(x):
+ the first continues to increase, while the second begins to decrease.
+ Near x=1, p_2(x) is no longer a good approximation to f(x).
+
+
+
+ However, the graph of p_4(x) also has a maximum near x=1,
+ and p_4(x) appears to be a good approximation to f(x) at least until x=2.
+
A table of the derivatives of f(x)=\sqrt{x} evaluated at x=4
diff --git a/ptx/sec_transformations.ptx b/ptx/sec_transformations.ptx
index 8123fee20..4796a64d4 100644
--- a/ptx/sec_transformations.ptx
+++ b/ptx/sec_transformations.ptx
@@ -2142,7 +2142,7 @@
Thus the desired transformation is defined on the rectangle D = [1,4]\times [1,2] and has an inverse given by T^{-1}(x,y) = (y/x,xy).
-
+
The region of integration in
A region in the first quadrant bounded by two hyperbolas, and two lines through the origin.
diff --git a/ptx/sec_trigint.ptx b/ptx/sec_trigint.ptx
index 0c84af962..74d1c8129 100644
--- a/ptx/sec_trigint.ptx
+++ b/ptx/sec_trigint.ptx
@@ -832,7 +832,7 @@
.
-
+ Video solution
diff --git a/ptx/sec_vector_intro.ptx b/ptx/sec_vector_intro.ptx
index 6d8469ef0..5a3dfcd16 100644
--- a/ptx/sec_vector_intro.ptx
+++ b/ptx/sec_vector_intro.ptx
@@ -511,7 +511,7 @@
component-wise.
-
+
Video presentation of (2 videos)
@@ -578,7 +578,7 @@
These are all sketched in .
-
+ Video solution
@@ -771,7 +771,7 @@
(when their initial points are the same).
-
+ Video solution
@@ -1128,7 +1128,7 @@
-
+ Video solution
diff --git a/ptx/sec_vvf.ptx b/ptx/sec_vvf.ptx
index 46ccae9c2..5b7671aaa 100644
--- a/ptx/sec_vvf.ptx
+++ b/ptx/sec_vvf.ptx
@@ -632,7 +632,7 @@
\vec r(t) = \vec p(t) + \vec c(t) = \la \cos(t) + t,-\sin(t) +1\ra,
which is graphed in .
-
+
Further examples with the Fundamental Theorem (4 videos)
-
-
-
The Fundamental Theorem of Line Integrals states that we can determine whether or not \vec F is conservative by determining whether or not \vec F has a potential function.
This can be difficult.
@@ -1477,6 +1472,11 @@
We state this simpler method as a theorem.
+
+
Further examples with the Fundamental Theorem (4 videos)
Illustrating the chain rule, and interpreting as matrix multiplication (see )
+
+
+
Using the Multivariable Chain Rule, Part II
@@ -539,11 +544,6 @@
-
-
diff --git a/ptx/sec_planes.ptx b/ptx/sec_planes.ptx
index 82578d290..afe81794b 100644
--- a/ptx/sec_planes.ptx
+++ b/ptx/sec_planes.ptx
@@ -301,7 +301,7 @@
-
+ Video solution
@@ -373,7 +373,7 @@
it is sketched in .
-
+
Sketching the plane in
@@ -465,7 +465,7 @@
The line and plane are sketched in .
-
+
The line and plane in
@@ -530,7 +530,7 @@
-
+ Video solution
diff --git a/ptx/sec_ratio_root_tests.ptx b/ptx/sec_ratio_root_tests.ptx
index 4c542b3a4..1609ece38 100644
--- a/ptx/sec_ratio_root_tests.ptx
+++ b/ptx/sec_ratio_root_tests.ptx
@@ -269,6 +269,11 @@
and does not work well with terms containing factorials.
+
+
Video presentation of
+
+
+
Root Test
@@ -308,11 +313,6 @@
-
-
Video presentation of
-
-
-
Applying the Root Test
diff --git a/ptx/sec_space_coord.ptx b/ptx/sec_space_coord.ptx
index f77920f3c..44250e449 100644
--- a/ptx/sec_space_coord.ptx
+++ b/ptx/sec_space_coord.ptx
@@ -684,7 +684,7 @@
and is bounded by planes in the y direction.
-
+