Quotient Rule and Chain Rule
The quotient rule handles division between functions. If y = f/g, then y' = f′g−fg′/g². This formula might look intimidating, but think of it as: (derivative of top × bottom) minus (top × derivative of bottom), all divided by (bottom squared).
For example, differentiating y = 5x2−3x+2/4x−8 requires applying the quotient rule carefully. The numerator becomes the difference between two products, which you can then simplify.
The chain rule is essential when functions are "nested" inside each other. When y = f(x)^n, the derivative is y' = nf(x)^n−1 × f'(x). You're essentially differentiating the outer function and multiplying by the derivative of the inner function.
For instance, to find y' for y = 7x2+9^4, you'd get y' = 47x2+9^3 × 14x = 56x7x2+9^3.
💡 Position, velocity, and acceleration are related through derivatives! If f(x) represents position, then f'(x) is velocity, and f''(x) is acceleration. This makes calculus incredibly useful for physics problems.
The chain rule often combines with other rules in complex problems. Being able to recognize when to use each rule will make solving differentiation problems much easier.