Inverse Trigonometric Functions - Other properties of inverse trig functions

  • Recap of Inverse Trigonometric Functions

    • Definition: Inverse function of a trigonometric function
    • Range of inverse trig functions
  • Domain and Range of Inverse Trigonometric Functions

    • Domain: Range of corresponding trig functions
    • Range: Restricted domains of inverse trig functions
  • Basic Properties of Inverse Trig Functions

    • Identity Property: sin^(-1)(sin(x)) = x
    • Identity Property: cos^(-1)(cos(x)) = x
    • Identity Property: tan^(-1)(tan(x)) = x
  • Odd and Even Properties of Inverse Trig Functions

    • Odd Property: sin^(-1)(-x) = -sin^(-1)(x)
    • Even Property: cos^(-1)(-x) = cos^(-1)(x)
    • Odd Property: tan^(-1)(-x) = -tan^(-1)(x)
  • Pythagorean Identities of Inverse Trig Functions

    • Pythagorean Identity: sin^(-1)(x) = cos^(-1)(√(1 - x^2))
    • Pythagorean Identity: cos^(-1)(x) = sin^(-1)(√(1 - x^2))
  • Examples: Identifying Domain and Range

    • Example 1: Find the domain and range of sin^(-1)(x)
    • Example 2: Find the domain and range of cos^(-1)(x)
  • Complementary Angles Property

    • Complementary Angles Property: sin^(-1)(x) + cos^(-1)(x) = π/2
    • Complementary Angles Property: tan^(-1)(x) + cot^(-1)(x) = π/2
  • Examples: Complementary Angles Property

    • Example 1: Find the value of sin^(-1)(3/5) + cos^(-1)(4/5)
    • Example 2: Find the value of tan^(-1)(2) + cot^(-1)(3)
  • Composition of Inverse Trig Functions

    • Composition Property: sin(sin^(-1)(x)) = x
    • Composition Property: cos(cos^(-1)(x)) = x
    • Composition Property: tan(tan^(-1)(x)) = x
  • Examples: Composition Property

    • Example 1: Prove that sin(sin^(-1)(x)) = x
    • Example 2: Prove that tan(tan^(-1)(x)) = x

Slide 11

  • Examples: Identifying Domain and Range
    • Example 1: Find the domain and range of sin^(-1)(x)
      • Domain: -1 ≤ x ≤ 1 (range of sin function)
      • Range: -π/2 ≤ sin^(-1)(x) ≤ π/2 (restricted range)
    • Example 2: Find the domain and range of cos^(-1)(x)
      • Domain: -1 ≤ x ≤ 1 (range of cos function)
      • Range: 0 ≤ cos^(-1)(x) ≤ π (restricted range)

Slide 12

  • Complementary Angles Property
    • Complementary Angles Property: sin^(-1)(x) + cos^(-1)(x) = π/2
      • The sine and cosine of complementary angles always add up to π/2
      • Useful in finding missing angles in right-angled triangles
    • Complementary Angles Property: tan^(-1)(x) + cot^(-1)(x) = π/2
      • The tangent and cotangent of complementary angles always add up to π/2
      • Used to find missing angles in right-angled triangles

Slide 13

  • Examples: Complementary Angles Property
    • Example 1: Find the value of sin^(-1)(3/5) + cos^(-1)(4/5)
      • Using the Complementary Angles Property: sin^(-1)(3/5) + cos^(-1)(4/5) = π/2
    • Example 2: Find the value of tan^(-1)(2) + cot^(-1)(3)
      • Using the Complementary Angles Property: tan^(-1)(2) + cot^(-1)(3) = π/2

Slide 14

  • Composition of Inverse Trig Functions
    • Composition Property: sin(sin^(-1)(x)) = x
      • The sine of the arcsine of x is x itself
    • Composition Property: cos(cos^(-1)(x)) = x
      • The cosine of the arccosine of x is x itself
    • Composition Property: tan(tan^(-1)(x)) = x
      • The tangent of the arctangent of x is x itself

Slide 15

  • Examples: Composition Property
    • Example 1: Prove that sin(sin^(-1)(x)) = x
      • Let y = sin^(-1)(x)
      • Then, sin(y) = x (definition of arcsine)
      • Taking the sine of both sides, sin(sin^(-1)(x)) = x
    • Example 2: Prove that tan(tan^(-1)(x)) = x
      • Let y = tan^(-1)(x)
      • Then, tan(y) = x (definition of arctangent)
      • Taking the tangent of both sides, tan(tan^(-1)(x)) = x

Slide 21

  • Derivatives of Inverse Trig Functions

    • Derivative of arcsin(x) = 1/√(1 - x^2)
    • Derivative of arccos(x) = -1/√(1 - x^2)
    • Derivative of arctan(x) = 1/(1 + x^2)
  • Integrals of Inverse Trig Functions

    • Integral of 1/√(1 - x^2) = arcsin(x) + C
    • Integral of -1/√(1 - x^2) = arccos(x) + C
    • Integral of 1/(1 + x^2) = arctan(x) + C
  • Logarithmic Properties of Inverse Trig Functions

    • Logarithmic Property: ln(1 + x) = arctan(x) + C
    • Logarithmic Property: ln(1 - x) = -arctan(x) + C
  • Properties of Inverse Hyperbolic Trig Functions

    • Inverse Hyperbolic Functions: arcsinh(x), arccosh(x), arctanh(x)
    • Similar properties as inverse trig functions

Slide 22

  • Derivatives of Inverse Trig Functions
    • Derivative of arcsin(x) = 1/√(1 - x^2)
      • Example: Find the derivative of y = arcsin(2x)
    • Derivative of arccos(x) = -1/√(1 - x^2)
      • Example: Find the derivative of y = arccos(3x)
    • Derivative of arctan(x) = 1/(1 + x^2)
      • Example: Find the derivative of y = arctan(4x)

Slide 23

  • Integrals of Inverse Trig Functions
    • Integral of 1/√(1 - x^2) = arcsin(x) + C
      • Example: Evaluate the integral ∫(1/√(1 - x^2)) dx
    • Integral of -1/√(1 - x^2) = arccos(x) + C
      • Example: Evaluate the integral ∫(-1/√(1 - x^2)) dx
    • Integral of 1/(1 + x^2) = arctan(x) + C
      • Example: Evaluate the integral ∫(1/(1 + x^2)) dx

Slide 24

  • Logarithmic Properties of Inverse Trig Functions
    • Logarithmic Property: ln(1 + x) = arctan(x) + C
      • Example: Prove that ln(1 + x) = arctan(x) + C
    • Logarithmic Property: ln(1 - x) = -arctan(x) + C
      • Example: Prove that ln(1 - x) = -arctan(x) + C

Slide 25

  • Properties of Inverse Hyperbolic Trig Functions
    • Inverse Hyperbolic Functions: arcsinh(x), arccosh(x), arctanh(x)
      • Similar to inverse trig functions, but for hyperbolic functions
      • Inverse Hyperbolic Identity: sinh(arcsinh(x)) = x
      • Inverse Hyperbolic Identity: cosh(arccosh(x)) = x
      • Inverse Hyperbolic Identity: tanh(arctanh(x)) = x

Slide 26

  • Properties of Inverse Hyperbolic Trig Functions (contd.)
    • Inverse Hyperbolic Identity: arcsinh(sinh(x)) = x
    • Inverse Hyperbolic Identity: arccosh(cosh(x)) = x, x ≥ 1
    • Inverse Hyperbolic Identity: arccosh(cosh(x)) = -x, x ≤ -1
    • Inverse Hyperbolic Identity: arctanh(tanh(x)) = x

Slide 27

  • Graphs of Inverse Trig Functions
    • Graph of y = sin^(-1)(x)
    • Graph of y = cos^(-1)(x)
    • Graph of y = tan^(-1)(x)

Slide 28

  • Graphs of Inverse Hyperbolic Trig Functions
    • Graph of y = sinh^(-1)(x)
    • Graph of y = cosh^(-1)(x)
    • Graph of y = tanh^(-1)(x)

Slide 29

  • Solving Equations Involving Inverse Trig Functions
    • Method: Convert inverse trig equation to a regular trig equation
    • Example: Solve the equation sin^(-1)(x) + cos^(-1)(x) = π/2
    • Example: Solve the equation tan^(-1)(x) = π/4

Slide 30

  • Summary
    • Inverse Trig Functions: arcsin(x), arccos(x), arctan(x)
    • Properties of Inverse Trig Functions
    • Derivatives and Integrals of Inverse Trig Functions
    • Logarithmic Properties of Inverse Trig Functions
    • Properties of Inverse Hyperbolic Trig Functions
    • Solving Equations Involving Inverse Trig Functions
    • Graphs of Inverse Trig Functions and Inverse Hyperbolic Trig Functions