Cue Column: Key Questions
- What are the 6 main differentiation techniques?
- When to use logarithmic differentiation?
- How to handle inverse trig derivatives?
- What is the chain rule pattern?
Notes Column: Differentiation in JEE requires mastery of six techniques: (1) direct formula application, (2) chain rule, (3) product/quotient rules, (4) implicit differentiation, (5) parametric differentiation, (6) logarithmic differentiation.
The chain rule d/dx[f(g(x))] = f'(g(x)) * g'(x) is the most critical. It extends to nested compositions: d/dx[f(g(h(x)))] = f'(g(h(x))) * g'(h(x)) * h'(x).
For inverse trig problems, ALWAYS simplify the expression using trigonometric substitution BEFORE differentiating. This transforms complex derivative computations into trivial ones.
Logarithmic differentiation is mandatory for f(x)^g(x) forms (like , x^(sin x), (sin x)^x). Take ln of both sides, differentiate implicitly, then multiply by y.
Parametric differentiation: dy/dx = . For the second derivative: / = [d/dt] / . Do NOT write / = — this is WRONG.
Summary: Master chain rule and inverse trig simplification — these cover 70% of JEE differentiation. Logarithmic differentiation handles the remaining exotic forms. Always simplify before differentiating.