Inverse Trigonometric Functions

  • Inverse Trigonometric Functions help us find the angle that produces a given value for a trigonometric ratio.
  • Inverse Trigonometric Functions are denoted by sin^(-1)(x), cos^(-1)(x), tan^(-1)(x), etc.
  • The range of Inverse Trigonometric Functions usually varies depending on the trigonometric function being used.

Example:

Given sin(x) = 1/2, find x.

  • Using the Inverse Sine function, we can write x = sin^(-1)(1/2).
  • According to the unit circle, the angle x where sin(x) = 1/2 is 30 degrees.

Inverse Trigonometric Functions - Properties

  • The domains of Inverse Trigonometric Functions are restricted in order to ensure that each function has a single-valued inverse.
  • The domains for the inverse functions are as follows:
    • sin^(-1)(x) is defined for x in [-1, 1]
    • cos^(-1)(x) is defined for x in [-1, 1]
    • tan^(-1)(x) is defined for all real values of x

Example:

Find the domain and range of the function y = tan^(-1)(x).

  • The domain of tan^(-1)(x) is all real values of x.
  • The range of tan^(-1)(x) is [-pi/2, pi/2].

Evaluating Inverse Trigonometric Functions

  • We can evaluate Inverse Trigonometric Functions either by using tables or using a calculator.
  • Inverse Trigonometric Functions are often expressed in radian measure.

Example:

Evaluate sin^(-1)(1).

  • The value of sin^(-1)(1) is pi/2 or 90 degrees.

Trigonometric Equations involving Inverse Functions

  • Trigonometric equations involving inverse functions can be solved in a similar way to regular trigonometric equations.
  • We may need to use properties of inverse functions to find all possible solutions.

Example:

Solve the equation sin^(-1)(2x) = pi/6.

  • Using the property of inverse functions, we get 2x = sin(pi/6) = 1/2.
  • Solving for x, we find x = 1/4.

Derivatives of Inverse Trigonometric Functions

  • The derivatives of Inverse Trigonometric Functions can be determined using standard differentiation rules and trigonometric identities.
  • The derivatives of the common Inverse Trigonometric Functions are as follows:
    • (d/dx) sin^(-1)(x) = 1 / sqrt(1 - x^2)
    • (d/dx) cos^(-1)(x) = -1 / sqrt(1 - x^2)
    • (d/dx) tan^(-1)(x) = 1 / (1 + x^2)

Example:

Find the derivative of the function y = cos^(-1)(2x).

  • Using the derivative formula, we have (d/dx) cos^(-1)(2x) = -1 / sqrt(1 - (2x)^2).
  • Simplifying further, we get (d/dx) cos^(-1)(2x) = -1 / sqrt(1 - 4x^2).

Integrals of Inverse Trigonometric Functions

  • The integrals of Inverse Trigonometric Functions can be determined using basic integration techniques and trigonometric identities.
  • The integrals of the common Inverse Trigonometric Functions are as follows:
    • ∫(1 / sqrt(1 - x^2)) dx = sin^(-1)(x) + C
    • ∫(-1 / sqrt(1 - x^2)) dx = cos^(-1)(x) + C
    • ∫(1 / (1 + x^2)) dx = tan^(-1)(x) + C

Example:

Find the integral of the function f(x) = 1 / (4 + 9x^2).

  • Using the integral formula, we have ∫(1 / (4 + 9x^2)) dx = (1/3)tan^(-1)(3x/2) + C.

Graphs of Inverse Trigonometric Functions

  • The graphs of Inverse Trigonometric Functions are often restricted to specific intervals due to their limited range.
  • The graphs of y = sin^(-1)(x), y = cos^(-1)(x), and y = tan^(-1)(x) have distinct characteristics and domains.

Example:

Graph the function y = sin^(-1)(x).

  • The graph of y = sin^(-1)(x) is a curve that starts at (-1, -pi/2) and ends at (1, pi/2). It is symmetrical about the line y = x.

Properties of Inverse Trigonometric Functions

  • Inverse Trigonometric Functions possess various properties that can be used for simplification and solving trigonometric equations.
  • Some of the important properties include:
    • sin(sin^(-1)(x)) = x, for all x in [-1, 1]
    • cos(cos^(-1)(x)) = x, for all x in [-1, 1]
    • tan(tan^(-1)(x)) = x, for all real x

Inverse Trigonometric Functions - Example

  • Find the value of cos^(-1)(sqrt(3)/2).
  • Solution: Using the inverse cosine function, we can write cos^(-1)(sqrt(3)/2) = pi/6 or 30 degrees.
  • The angle where cos(x) = sqrt(3)/2 is pi/6 or 30 degrees.

Inverse Trigonometric Functions - Equations

  • Inverse Trigonometric Functions can be used to solve trigonometric equations.
  • We can write equations involving inverse functions in terms of the trigonometric ratio.
  • Solving these equations may require using trigonometric identities and simplifying.

Example:

Solve the equation cos^(-1)(x) = pi/4.

  • Using the property of inverse functions, we get x = cos(pi/4) = sqrt(2)/2.
  • Solving for x, we find x = sqrt(2)/2.

Inverse Trigonometric Functions - Derivatives

  • The derivatives of Inverse Trigonometric Functions can be determined using standard differentiation rules and trigonometric identities.
  • The derivatives of the common Inverse Trigonometric Functions are as follows:
    • (d/dx) sin^(-1)(x) = 1 / sqrt(1 - x^2)
    • (d/dx) cos^(-1)(x) = -1 / sqrt(1 - x^2)
    • (d/dx) tan^(-1)(x) = 1 / (1 + x^2)

Example:

Find the derivative of the function y = tan^(-1)(3x).

  • Using the derivative formula, we have (d/dx) tan^(-1)(3x) = 3 / (1 + (3x)^2).
  • Simplifying further, we get (d/dx) tan^(-1)(3x) = 3 / (1 + 9x^2).

Inverse Trigonometric Functions - Integrals

  • The integrals of Inverse Trigonometric Functions can be determined using basic integration techniques and trigonometric identities.
  • The integrals of the common Inverse Trigonometric Functions are as follows:
    • ∫(1 / sqrt(1 - x^2)) dx = sin^(-1)(x) + C
    • ∫(-1 / sqrt(1 - x^2)) dx = cos^(-1)(x) + C
    • ∫(1 / (1 + x^2)) dx = tan^(-1)(x) + C

Example:

Find the integral of the function f(x) = 1 / (1 + x^2).

  • Using the integral formula, we have ∫(1 / (1 + x^2)) dx = tan^(-1)(x) + C.

Inverse Trigonometric Functions - Graphs

  • The graphs of Inverse Trigonometric Functions have distinct shapes and characteristics.
  • The domain and range of these graphs are determined by the range of the inverse functions.
  • The graphs often have different slopes and concavity.

Example:

Graph the function y = cos^(-1)(x).

  • The graph of y = cos^(-1)(x) is a curve that starts at (1, 0) and ends at (-1, pi). It is concave down.

21. Inverse Trigonometric Functions - Example

  • Find the value of tan^(-1)(1).
  • Solution: Using the inverse tangent function, we can write tan^(-1)(1) = pi/4 or 45 degrees.
  • The angle where tan(x) = 1 is pi/4 or 45 degrees.

22. Inverse Trigonometric Functions - Equations

  • Inverse Trigonometric Functions can be used to solve trigonometric equations.
  • We can write equations involving inverse functions in terms of the trigonometric ratio.
  • Solving these equations may require using trigonometric identities and simplifying.

Example:

Solve the equation tan^(-1)(2x) = pi/3.

  • Using the property of inverse functions, we get 2x = tan(pi/3) = sqrt(3).
  • Solving for x, we find x = sqrt(3)/2.

23. Inverse Trigonometric Functions - Derivatives

  • The derivatives of Inverse Trigonometric Functions can be determined using standard differentiation rules and trigonometric identities.
  • The derivatives of the common Inverse Trigonometric Functions are as follows:
    • (d/dx) sin^(-1)(x) = 1 / sqrt(1 - x^2)
    • (d/dx) cos^(-1)(x) = -1 / sqrt(1 - x^2)
    • (d/dx) tan^(-1)(x) = 1 / (1 + x^2)

Example:

Find the derivative of the function y = sin^(-1)(2x).

  • Using the derivative formula, we have (d/dx) sin^(-1)(2x) = 2 / sqrt(1 - (2x)^2).
  • Simplifying further, we get (d/dx) sin^(-1)(2x) = 2 / sqrt(1 - 4x^2).

24. Inverse Trigonometric Functions - Integrals

  • The integrals of Inverse Trigonometric Functions can be determined using basic integration techniques and trigonometric identities.
  • The integrals of the common Inverse Trigonometric Functions are as follows:
    • ∫(1 / sqrt(1 - x^2)) dx = sin^(-1)(x) + C
    • ∫(-1 / sqrt(1 - x^2)) dx = cos^(-1)(x) + C
    • ∫(1 / (1 + x^2)) dx = tan^(-1)(x) + C

Example:

Find the integral of the function f(x) = 1 / (1 + x^2).

  • Using the integral formula, we have ∫(1 / (1 + x^2)) dx = tan^(-1)(x) + C.

25. Inverse Trigonometric Functions - Graphs

  • The graphs of Inverse Trigonometric Functions have distinct shapes and characteristics.
  • The domain and range of these graphs are determined by the range of the inverse functions.
  • The graphs often have different slopes and concavity.

Example:

Graph the function y = tan^(-1)(x).

  • The graph of y = tan^(-1)(x) is a curve that starts at (-infinity, -pi/2) and ends at (infinity, pi/2). It approaches pi/2 as x approaches infinity and approaches -pi/2 as x approaches negative infinity.

26. Inverse Trigonometric Functions - Properties

  • Inverse Trigonometric Functions possess various properties that can be used for simplification and solving trigonometric equations.
  • Some of the important properties include:
    • sin(sin^(-1)(x)) = x, for all x in [-1, 1]
    • cos(cos^(-1)(x)) = x, for all x in [-1, 1]
    • tan(tan^(-1)(x)) = x, for all real x

27. Inverse Trigonometric Functions - Example

  • Find the value of sin^(-1)(1/2).
  • Solution: Using the inverse sine function, we can write sin^(-1)(1/2) = pi/6 or 30 degrees.
  • The angle where sin(x) = 1/2 is pi/6 or 30 degrees.

28. Inverse Trigonometric Functions - Equations

  • Inverse Trigonometric Functions can be used to solve trigonometric equations.
  • We can write equations involving inverse functions in terms of the trigonometric ratio.
  • Solving these equations may require using trigonometric identities and simplifying.

Example:

Solve the equation sin^(-1)(2x) = pi/4.

  • Using the property of inverse functions, we get 2x = sin(pi/4) = sqrt(2)/2.
  • Solving for x, we find x = sqrt(2)/4.

29. Inverse Trigonometric Functions - Derivatives

  • The derivatives of Inverse Trigonometric Functions can be determined using standard differentiation rules and trigonometric identities.
  • The derivatives of the common Inverse Trigonometric Functions are as follows:
    • (d/dx) sin^(-1)(x) = 1 / sqrt(1 - x^2)
    • (d/dx) cos^(-1)(x) = -1 / sqrt(1 - x^2)
    • (d/dx) tan^(-1)(x) = 1 / (1 + x^2)

Example:

Find the derivative of the function y = cos^(-1)(2x).

  • Using the derivative formula, we have (d/dx) cos^(-1)(2x) = -2 / sqrt(1 - (2x)^2).
  • Simplifying further, we get (d/dx) cos^(-1)(2x) = -2 / sqrt(1 - 4x^2).

30. Inverse Trigonometric Functions - Integrals

  • The integrals of Inverse Trigonometric Functions can be determined using basic integration techniques and trigonometric identities.
  • The integrals of the common Inverse Trigonometric Functions are as follows:
    • ∫(1 / sqrt(1 - x^2)) dx = sin^(-1)(x) + C
    • ∫(-1 / sqrt(1 - x^2)) dx = cos^(-1)(x) + C
    • ∫(1 / (1 + x^2)) dx = tan^(-1)(x) + C

Example:

Find the integral of the function f(x) = 1 / (4 + 9x^2).

  • Using the integral formula, we have ∫(1 / (4 + 9x^2)) dx = (1/3)tan^(-1)(3x/2) + C.