Math 141 · Lesson 6
Drag points on a standard plot and compare their images, the same points on the semi-log and log-log plots. Judge which plot is linear. The values of k and C are worked out from the line through the first and last points.
Math 141 · Lesson 8
Move the sliders for the four parameters of a sine model and the landmarks move with the curve. Then estimate the parameters of a sine model for TemperaturesDanville or SunsetGreenwich by hand from points clicked on the plot.
Math 141 · Lesson 9
Move the sliders for the four parameters of a sigmoid and the landmarks move with the curve: the two levels, the whole rise, the halfway and five-sixths crossings and the spread. Use the tool with no data or over a Lesson 9 dataset.
Math 141 · Lesson 10
Lay a linear, exponential, power, sine or sigmoid model over a dataset on the standard, semi-log and log-log plots at once. Move a parameter and the curve changes on all three plots.
Math 141 · Lesson 15
Drag two vectors on a grid and draw the result of each operation, with the component arithmetic and the R code beside the picture.
Math 141 · Lesson 16
Type a field F̄(x, y) and move the input point around the plane to get the output vector at each point. The field is also drawn as arrows and as animated airflow.
Math 141 · Lesson 17
Step through Ax as a linear combination of the columns of A, with animated scaling and adding. The Abstract m × n mode runs the same steps for a general matrix.
Math 141 · Lesson 19
Build x1u1 + x2u2 tip to tail with two sliders, place a target and step through the hand solution. When the two vectors are parallel, the grid of combinations collapses onto one line.
Math 141 · Lesson 20
Drag two vectors to get their dot product worked out component by component. Turn on the sign regions to see where the dot product is positive, zero or negative.
Math 141 · Lesson 21
Drag two vectors to get the projection of v̄ onto ū, the closest multiple of ū to v̄. The worked solution, the residual and the R code update as the vectors move.
Math 141 · Lesson 22
Fit a line by hand to a dataset and track the length of the residual vector as the line moves. Then compare the drawn line with the least squares line.