This is the boss. No calculator: the function is a bracket times a power of a bracket, $(x + c)(ax + b)^n$, with small whole numbers and $n$ equal to 2 or 3, the point is $-1$, 0, 1 or 2, and every number fits in your head. One function, one long inspection, and every answer feeds the next: read the shape and name the outer rule, name the product rule, name the chain rule for the power, find the height $f(x_0)$, find the slope $f'(x_0)$ from the two rules you named, name the tangent line, and read off where that line crosses the $y$-axis or where it sits one unit along.

Everything in the chapter rides in here: the outermost operation read before any rule runs, $f'g + fg'$ with two terms, $n u^{n-1}$ times the inner slope with the inner slope not dropped, and the tangent line $y = f(x_0) + f'(x_0)(x - x_0)$ from module 2 with the slope a NUMBER. Write each line down as you go; a slip in line four walks all the way to line seven. 5★ under par is the chapter crown.