Content Curator
Inverse Trigonometric Functions are the inverse functions of the basic trigonometric functions.
- The basic trigonometric functions include sine, cosine, tangent, cotangent, secant, and cosecant.
- These functions are also known as arcus functions, anti-trigonometric functions, or cyclometer functions.
- Inverse trigonometry is applied in various fields such as physics, engineering, geometry, navigation, geometry, aviation, marine biology, etc.
- Inverse Trigonometry is useful for obtaining angles of a triangle from any trigonometric function.
Table of Content |
Key Terms: Inverse Trigonometric Functions, Functions, Perpendicular,cotangent, secant, Tangent, trigonometric, Traingle, sine, cosine, tangent, cotangent, secant, cosecant
Definition of Inverse Trigonometric Functions
[Click Here for Sample Questions]
Inverse trigonometric Functions are known as the anti-trigonometric functions as they are the inverse of trigonometric functions.
- They are also known as the ''Arc Functions''.
- Inverse Trigonometric Functions perform opposite functions of the trigonometric Functions.
- These functions are useful for finding angles when any two sides of a right-angled triangle are given.
- The inverse trigonometric functions are written with the prefix 'arc'.
Also Read:
Formulas Of Inverse Trigonometric Functions
[Click Here for Previous Year Questions]
Inverse Trigonometric Formulas are necessary to solve the questions.
Some basic trigonometric formulas are-:
- sin-1(-x) = -sin-1(x), x ∈ [-1, 1]
- cos-1(-x) = π -cos-1(x), x ∈ [-1, 1]
- tan-1(-x) = -tan-1(x), x ∈ R
- cot-1(-x) = π – cot-1(x), x ∈ R
- sec-1(-x) = π -sec-1(x), |x| ≥ 1
- cosec-1(-x) = -cosec-1(x), |x| ≥ 1
- sin-1x + cos-1x = π/2, x ∈ [-1,1]
- tan-1x+ cot-1x = π/2, x ∈ R
- sec-1x + cosec-1x = π/2, x ∈ R - [-1,1]
- sin-1x = cosec-11/x, x ∈ R - (-1,1)
- cos-1x = sec-11/x, x ∈ R - (-1,1)
- tan-1x = cot-11/x, x > 0
- tan-1x = - π + cot-1 x, x < 0
- sin-1x + sin-1y = sin-1(x.√(1 - y2) + y√(1 - x2))
- sin-1x - sin-1y = sin-1(x.√(1 - y2) - y√(1 - x2))
- cos-1x + cos-1y = cos-1(xy - √(1 - x2).√(1 - y2))
- cos-1x - cos-1y = cos-1(xy + √(1 - x2).√(1 - y2))
- tan-1x + tan-1y = tan-1(x + y)/(1 - xy), if xy < 1
- tan-1x + tan-1y = tan-1(x - y)/(1 + xy), if xy > - 1
Graphs Of Inverse Trigonometric Functions
[Click Here for Sample Questions]
The graphs of inverse trigonometric functions are given below
sin-1x Graph
sin-1x is the inverse of the sine function. It is denoted by the graph as shown below-:
- Domain = -1 ≤ x ≤ 1
- Range = -π/2 ≤ y ≤ π/2
cos-1(x) Graph
cos-1(x) is the inverse of the cosine function. It is denoted by the graph as shown below-:
- Domain = -1≤ x ≤1
- Range = 0 ≤ y ≤ π
tan-1(x) Graph
tan-1(x) is the inverse of the tangent function. It is denoted by the graph as shown below-:
- Domain = -∞ < x < ∞
- Range =-π/2 < y < π/2
cosec-1(x) Graph
cosec-1(x) is the inverse of the Cosecant function. It is denoted by the graph as shown below-:
- Domain = -∞ ≤ x ≤ -1 or 1 ≤ x ≤ ∞
- Range = -π/2 ≤ y ≤ π/2, y ≠ 0
sec-1(x) Graph
sec-1(x) is the inverse of the Secant function. It is denoted by the graph as shown below-:
- Domain = -∞ ≤ x ≤ -1 or 1 ≤ x ≤ ∞
- Range 0 ≤ y ≤ π, y ≠ π/2
cot-1(x) Graph
cot-1(x) is the inverse of the Cotangent function. It is denoted by the following graph-:
- Domain = -∞ < x < ∞
- Range = 0 < y < π
Domain and Range Of Inverse Trigonometric Functions
[Click Here for Previous Year Questions]
The graphs help in comprehending and comparing different functions.
- The domain of a function is shown along the x-axis of a graph, while the range of a function is denoted by the y-axis of the graph.
- Domain and range give us the principle value of the inverse trigonometric function.
The domain and range of different functions are as follows-:
Function | Domain | Range |
---|---|---|
y = sin-1(x) | −1 ≤ x ≤ 1 | − π/2 ≤ y ≤ π/2 |
y=cos-1(x) | −1 ≤ x ≤ 1 | 0 ≤ y ≤ π |
y=tan-1(x) | All real numbers | − π/2 < y < π/2 |
y=cosec-1(x) | x ≤ −1 or 1 ≤ x | −π/2≤y<0 or 0 |
y = sec-1(x) | x ≤ −1 or 1 ≤ x | 0≤y<π/2 or π/2 |
y=cot-1(x) | All real numbers | 0 < y < π |
Derivative Of Inverse Trigonometric Function
[Click Here for Sample Questions]
Inverse Trigonometric Functions are integral in Calculus.
- The derivatives of inverse trigonometric functions are used to solve many questions.
- The derivatives of these functions are first-order derivatives.
The Derivative of the functions are as follows-:
Inverse Trigonometric Function | dy/dx |
---|---|
y = sin-1(x) | 1/√(1-x2) |
y = cos-1(x) | -1/√(1-x2) |
y = tan-1(x) | 1/(1+x2) |
y = cot-1(x) | -1/(1+x2) |
y = sec-1(x) | 1/[|x|√(x2-1)] |
y = cosec-1(x) | -1/[|x|√(x2-1)] |
Important Topics for JEE MainAs per JEE Main 2024 Session 1, important topics included in the chapter Inverse Trigonometric Functions are as follows:
Some memory based important questions asked in JEE Main 2024 Session 1 include:
|
Things to Remember
- Inverse Trigonometric Functions are the inverse of the basic trigonometric functions like sin x, cosx, tan x, cosec x, sec x, and cot x.
- Inverse Trigonometry is used to find the angle of a right-angled triangle when two sides are given.
- Inverse Trigonometric functions are also known as arcus functions, anti-trigonometric functions, or cyclometer functions.
- The domain of a function is represented along the x-axis, while the Range of a function is represented along the y-axis.
- Derivatives of the Inverse Trigonometric Functions are also an important part of calculus.
- They are used in solving numerous problems.
Previous Year Questions
- If tan−1xtan−1x + tan−1ytan−1y = 2π32π3 , then cot−1xcot−1x + cot−1ycot−1y is equal t
- If sin−1x+sin−1y=π2 , then cos−1x+cos−1y is equal to
- cos−1(−12)−2sin−1(12)+3cos−1(−1√2)−4tan−1(−1) equals
- The period of sin4x+cos4x is
- If 2tan−1(cosx)=tan−1(2cosecx) then sinx+cosx is equal to
- The period of tan3θ is
- ∫ex(1+sinx)1+cosxdx=….[COMEDK UGET 2011]
- If tan(x+y)=33 and x=tan−13, then y is…..[COMEDK UGET 2015]
- cot−1(21)+cot−1(13)+cot−1(−8)=…...[COMEDK UGET 2015]
- tan(cos−1(15√2)−sin−1(4√17)) is….…..[COMEDK UGET 2015]
- If 12≤x≤1,12≤x≤1, then cos−1x+cos−1(x2+√3−3x22)=...[COMEDK UGET 2010]
- If cos−1x+cos−1y+cos−1z=3π, then xy+yz+zx is...[COMEDK UGET 2011]
- Define f (x) = min{x^2 + 1, x + 1] for.xe∈R. Then 1∫−1f(x)dx is...[COMEDK UGET 2005]
- The value of the integral π/4∫01+sin2cos3xdx is….[COMEDK UGET 2005]
- tan−1(1x+y)+tan−1(yx2+xy+1)=…...[COMEDK UGET 2011]
- tan[12sin−1(2x1+x2)+12cos−1(1−x21+x2)]=….[COMEDK UGET 2007]
- The value of tan−1√2+√3−√2−√3√2+√3+√2−√3….[COMEDK UGET 2008]
- The value of cot−1{√1−sinx+√1+sinx√1−sinx−√1+sinx}(0<x<π2) is
- In a ΔABC, if A=tan−12 and B=tan−13 , then C=
- sin−1(1√e)>tan−1(1√π)sin−1(1e)>tan−1(1π) sin−1x>tan−1ysin−1x>tan−1y for x>y,∀x,y∈(0,1)
Sample Questions
Ques. Prove that tan-1 2/11 + tan-1 7/24 = tan-1 1/2. (4 marks)
Ans. By using the formula tan-1 x + tan-1 y = tan-1 (x + y) / (1 - xy)
We get, LHS = tan-1 2/11 + tan-1 7/24
= tan-1 [(2/11 + 7/24) / (1 - (2/11). (7/24)]
= tan-1 [((48 + 77) / 264) / ((264 - 14) / 264)]
On simplifying the terms,
= tan-1 (125 / 250)
= tan-1(1 / 2)
= RHS
Ques. Find the value of x for sin(x) = 2. (2 marks)
Ans. Given, sin (x) = 2
⇒ x =sin-1(2), which is not possible.
Hence, there is no value of x for which sin x = 2, so the domain of sin-1x is -1 to 1 for the values of x.
Ques. Find the value of tan (sin-1 3/5 + cot-1 3/2). (5 marks)
Ans. Here the basic trigonometric function of sin x = y can be changed to x = sin-1 y
Let sin-1 3/5 = x
⇒ sin x = 3/5
Then, cos x = √ 1 - sin2 x
= 4/5
⇒ sec x = 5/4
Therefore, tan x = √ sec2 x - 1
= √ ( 25/16) - 1
= 3 / 4
x = tan-1 3/4
sin-1 3 / 5 = tan-1 3 / 4 ....(1)
Now, cot-1 3 / 2 = tan-1 2 / 3 ....(2)
By using equation (1) and (2)
tan (sin-1 3/5 + cot-1 2/3) = tan (tan-1 3/4 + tan-1 2/3)
= tan [tan-1 (3/4 + 2/3) / (1 - (3/4).(2/3)]
= tan (tan-1 17 / 6)
= 17 / 6
Ques. Find the values of tan-1 √3 - cot-1 (- √3). (4 marks)
Ans. Here the basic trigonometric function of sinx = y, can be changed to x = sin-1 y
Let tan-1 √3 = x
So, tan x = √3
= tan π / 3
where π / 3 ∈ (- π/2, π/2)
So, tan-1 √3 = π/3
Let us assume cot-1 (- √3) = y
Hence, cot y = (- √3)
= - cot (π / 6)
= cot (π - π / 6)
= cot (5π / 6)
Since, Range of principal value of cot-1 x = (0, π)
Therefore, cot-1(- √3) = (5π / 6)
Then, tan-1 √3 - cot-1 (- √3)
= π / 3 - 5π / 6
= - π / 2
Ques. Prove that 3 sin-1 x = sin-1 (3x - 4x3), x ∈ [- 1/2, 1/2]. (4 marks)
Ans. The basic trigonometric function of Sin θ = y can be changed to θ = sin-1 y
Let x =sin θ
Hence, sin-1 (x) = θ
Now,
RHS = sin-1 (3x - 4x3)
Using the trigonometric function
sin 3 θ = 3 sin θ - 4 sin3 θ
= sin-1 (3sin θ - 4sin3 θ)
= sin-1 (sin 3θ)
= 3 θ
= 3 sin-1 x
= LHS
Ques. Find sin (cos-1 3/5). (2 marks)
Ans. Let cos-1 3/5 = x
⇒ cos x = 3/5
We have, sin x = √(1 – cos2 x)
⇒ sin x = √(1 – 9/15) = 4/5
⇒ sin x = sin (cos-1 3/5) = 4/5
Ques. Solve: 2 tan-1 (cos x) = tan-1 (2cosec x). (4 marks)
Ans. Basic trigonometric function of sin θ = y can be changed to θ = sin-1 y
It is given that 2 tan-1 (cos x)
= tan-1 (2 cosec x).
Since, 2 tan-1 (x) = tan-1 2x/(1 + x2)
Hence,
⇒ tan-1 [(2 cos x)/(1- cos2 x)]
= tan-1 (2 cosec x)
⇒ (2 cos x) / (sin2 x)
= 2/sin x
⇒ cos x = sin x
⇒ tanx = 1
⇒ tan x
= tan π/4
Therefore,
x = nπ + π/4, where n ∈ Z
Ques. Find the value of sin-1(sin π/6). (1 mark)
Ans. From identity sin-1(sin x) = x, we have
sin-1(sin π/6) = π/6
For Latest Updates on Upcoming Board Exams, Click Here: https://t.me/class_10_12_board_updates
Do Check Out:
Comments