Integral Calculus By Das And Mukherjee Pdf Info4️⃣ TRIG INTEGRALS • Powers of sin/cos: - If odd power of sin → u = cos. - If odd power of cos → u = sin. • Both even → use identities: sin²x = (1‑cos2x)/2, cos²x = (1+cos2x)/2 • Products sin·cos → use substitution u = sin or cos. 3️⃣ PARTIAL FRACTIONS • Proper rational function required. • Factor denominator completely. • Write A/(x‑a)+B/(x‑b)… (linear) or (Cx+D)/(quadratic) (irreducible). • Solve for constants (equate coefficients or plug‑in). 2️⃣ INTEGRATION BY PARTS • Formula: ∫u dv = uv – ∫v du • Choose u = “algebraic” (poly, log) → du simpler. • dv = “trig, exp, power” → v easy. |