Differential And Integral Calculus By Feliciano And Uy Chapter 4 Jun 2026

Using logarithmic differentiation for functions where the variable appears in both the base and the exponent.

By the end of this chapter, you should be able to derive trigonometric functions (sine, cosine, tangent, cotangent, secant, cosecant) and solve basic application problems (slopes, rates of change, velocity).

The authors begin by establishing the rules governing the interaction between derivatives and basic arithmetic operations. These theorems form the bedrock of differential calculus.

Find two numbers whose sum is 20 and product is maximum. Solution: (x + y = 20), (P = xy = x(20-x) = 20x - x^2) (P' = 20 - 2x = 0) → (x=10, y=10), max (P=100) These theorems form the bedrock of differential calculus

They emphasize the negative signs for cosine, cotangent, and cosecant. Do not forget them on exams.

( y = x^2 \tan x )

Chapter 4 expands your mathematical toolkit. The primary objective is to transform non-standard integrands into standard, recognizable forms. Mastery of this chapter requires algebraic agility, a strong grasp of trigonometric identities, and keen pattern recognition. 2. Integration by Substitution (u-Substitution) Do not forget them on exams

Chapter 4 concludes with Concavity and Inflection Points. This section deals with the "shape" of the graph—whether it opens upward or downward. Finding the point where the concavity changes, known as the inflection point, provides a complete picture of the function’s behavior.

If you are unsure of your answer to an integration problem, differentiate your result. If you do not end up with the original integrand, you made an error during integration.

Feliciano and Uy introduce integration not as an isolated concept, but as the direct inverse operation of differentiation. Just as subtraction undoes addition, and division undoes multiplication, integration reverses the process of finding a derivative. and division undoes multiplication

This section details how to differentiate the six core trigonometric functions using the Chain Rule: Cosine: Tangent: Cotangent: Secant: Cosecant: Walkthrough Example Differentiate Apply the power rule: Apply the cotangent rule: Simplify terms: 3. Inverse Trigonometric Functions (Section 4.3)

Forgetting to simplify logarithmic expressions (