Then checked the solution in the back: — ( y = [\sin(4x)]^3 ) Let ( u = \sin(4x) ), then ( y = u^3 ), ( \frac{dy}{du} = 3u^2 ) ( \frac{du}{dx} = \cos(4x) \cdot 4 ) (chain rule again inside) ( \frac{dy}{dx} = 3[\sin(4x)]^2 \cdot 4\cos(4x) = 12\sin^2(4x)\cos(4x) ) ✓ She had gotten it right — but the solution reminded her to explicitly show the inner chain rule on (4x), a step she often rushed. A Week Later — The Improvement Mia did two chapters per night. On Wednesday, she tackled implicit differentiation : Problem 47 — Find ( \frac{dy}{dx} ) for ( x^2 y^3 + \sin(y) = 5x ) She wrote:
Solution matched perfectly. For the first time, she didn’t forget the ( \frac{dy}{dx} ) on the (y^3) term. The final exam had a related rates problem she’d dreaded: A spherical balloon is inflated at 10 cm³/s. How fast is the radius increasing when ( r = 5 ) cm? Mia wrote calmly:
Mia wasn’t amused. The problem wasn’t understanding big ideas — limits, derivatives, integrals made sense in lecture. It was the mechanics . Chain rule with nested exponentials? Implicit differentiation gone wrong? Definite integrals where she’d forget the constant? Little errors snowballed into wrong answers. Then checked the solution in the back: —
No panic. No algebra mistake. Just solid, drilled-in calculus skills. Mia scored 86% on the final. Her overall grade rose to a B+. More importantly, she stopped fearing calculus — she started enjoying the precision.
I’m unable to provide a PDF download of Essential Calculus Skills Practice Workbook with Full Solutions by Chris McMullen, as that would likely violate copyright law. However, I can offer a detailed, original story about a student using that workbook to master calculus — and include a few sample problems with full solutions in the style of McMullen’s approach. Mia stared at her screen. Midterm scores were posted: Calculus I — 58% . The class average was 72. She had never failed a math test in her life. For the first time, she didn’t forget the
That night, she found a recommendation on a math forum: “Essential Calculus Skills Practice Workbook with Full Solutions by Chris McMullen — no fluff, just 100+ problems with step-by-step answers. Perfect for drilling weak spots.”
She later recommended McMullen’s workbook to Leo, who was struggling with integration. Leo’s text back: “Why didn’t you give me this sooner?” If you’d like to practice in McMullen’s direct style, here are three problems with full solutions: 1. Power Rule & Negative Exponents Problem : Differentiate ( f(x) = \frac{5}{x^3} - 2\sqrt{x} ) Mia wrote calmly: Mia wasn’t amused
Volume of sphere: ( V = \frac{4}{3} \pi r^3 ) Differentiate w.r.t. (t): ( \frac{dV}{dt} = 4\pi r^2 \frac{dr}{dt} ) Given ( \frac{dV}{dt} = 10 ), ( r = 5 ): ( 10 = 4\pi (25) \frac{dr}{dt} ) ( 10 = 100\pi \frac{dr}{dt} ) ( \frac{dr}{dt} = \frac{1}{10\pi} ) cm/s.
So: ( 2x y^3 + 3x^2 y^2 \frac{dy}{dx} + \cos(y) \frac{dy}{dx} = 5 )
Using product rule on first term: ( 2x \cdot y^3 + x^2 \cdot 3y^2 \frac{dy}{dx} )
[ \frac{d}{dx}[x^2 y^3] + \frac{d}{dx}[\sin(y)] = \frac{d}{dx}[5x] ]