Despite the title, I struggle to see who exactly this was written for.
The Javascript widgets are quite neat. Fiddling around with parameters, and receiving instant graphical feedback, is great for developing an intuitive understanding. But I find that the writing has several issues that probably make it less clear to beginners than your average calculus textbook:
The writing is very brief, with typical mathematical terseness. This is usually a good thing, since it lets you be very exact in your definitions. But to be accessible to a beginner, this writing needs to be backed up with concrete examples, and preferably a picture or two. In most cases I find that it isn't, so the reader needs to internalize a lot of things on their own before being able to move on.
The text is also sparse on showing its work. A positive example is near the bottom of 5.1, showing how to derive the quotient rule, but most of the time it looks more like example 1 in 6.1, with a lot of information given inline before actually applying the mentioned operations to the expression:
> Suppose we substitute the function g which has values given by g(x) = x² + 1 into the function f which takes values f(x) = x³ − 3.
> The substituted function f(g) has values f(g(x)) = (x² + 1)³ − 3.
> Let us compute the derivative of this function. The derivative of f(s) with respect to s is 3s², while the derivative of g(x) with respect to x is 2x.
> If we set s = g(x) which is x² + 1, and take the product of these two we get:
> [expression]
This type of mental expression manipulation is fine for someone that's had practice with it, but probably not for a beginner, who would gain a lot from having these kinds of things written out in a more structured way.
In these aspects, I find the text less clear than the calculus textbook i used at university (which was not directed toward beginners or artists).
I agree a lot with prvc's comment[0] about being able to fill in the gaps, in that the terseness and handwaviness can make this look like a beginner-friendly version to someone that already is familiar with the subject, but I don't think changing tone is enough to make something beginner-friendly.
The Javascript widgets are quite neat. Fiddling around with parameters, and receiving instant graphical feedback, is great for developing an intuitive understanding. But I find that the writing has several issues that probably make it less clear to beginners than your average calculus textbook:
The writing is very brief, with typical mathematical terseness. This is usually a good thing, since it lets you be very exact in your definitions. But to be accessible to a beginner, this writing needs to be backed up with concrete examples, and preferably a picture or two. In most cases I find that it isn't, so the reader needs to internalize a lot of things on their own before being able to move on.
The text is also sparse on showing its work. A positive example is near the bottom of 5.1, showing how to derive the quotient rule, but most of the time it looks more like example 1 in 6.1, with a lot of information given inline before actually applying the mentioned operations to the expression:
> Suppose we substitute the function g which has values given by g(x) = x² + 1 into the function f which takes values f(x) = x³ − 3.
> The substituted function f(g) has values f(g(x)) = (x² + 1)³ − 3.
> Let us compute the derivative of this function. The derivative of f(s) with respect to s is 3s², while the derivative of g(x) with respect to x is 2x.
> If we set s = g(x) which is x² + 1, and take the product of these two we get:
> [expression]
This type of mental expression manipulation is fine for someone that's had practice with it, but probably not for a beginner, who would gain a lot from having these kinds of things written out in a more structured way.
In these aspects, I find the text less clear than the calculus textbook i used at university (which was not directed toward beginners or artists).
I agree a lot with prvc's comment[0] about being able to fill in the gaps, in that the terseness and handwaviness can make this look like a beginner-friendly version to someone that already is familiar with the subject, but I don't think changing tone is enough to make something beginner-friendly.
0: https://news.ycombinator.com/item?id=20435238