Solve Inverse Trig Function with Domain [-π/2, π/2] | Step-by-Step Guide

AI Thread Summary
The discussion focuses on finding the inverse of the function f(x) = 3x + 1 + sin(x) within the domain [-π/2, π/2]. Participants clarify that the task is to determine f^{-1}(1) by solving the equation 3x + 1 + sin(x) = 1. It is emphasized that instead of finding the full inverse function, one can directly find the x value that satisfies the equation. The conversation highlights the importance of recognizing special cases that may simplify the problem-solving process. Overall, the main goal is to solve for x in the context of the given function and domain.
togame
Messages
18
Reaction score
0

Homework Statement


My problem is as follows:
find the inverse of
3x+1+\sin(x) with the domain [-\frac{\pi}{2},\frac{\pi}{2}]


Homework Equations





The Attempt at a Solution


for this would I just try to solve as normal by setting y=f(x) then using the fact that \arcsin(x) = y or is this the wrong way of solving this?
 
Physics news on Phys.org
togame said:

Homework Statement


My problem is as follows:
find the inverse of
3x+1+\sin(x) with the domain [-\frac{\pi}{2},\frac{\pi}{2}]


Homework Equations





The Attempt at a Solution


for this would I just try to solve as normal by setting y=f(x) then using the fact that \arcsin(x) = y or is this the wrong way of solving this?

You're not going to be able to solve the equation y = f(x) = 3x + 1 + sin(x) for x (to get the inverse x = f-1(y).
What is the exact problem statement? It might be that you are misreading what is being asked for in this problem.
 
The exact wording for this problem:
f(x) = 3x + 1 + \sin(x) with domain [-\pi/2, \pi/2]. Without your calculator, determine the value of f^{-1}(1).

Since this is an inverse function, I was going to try to solve for the inverse function, then solve for f^{-1}(1)
 
How is this question related to a problem which requires you to:
Solve f(x)=1\text{ for }x\,.​
?
 
SammyS said:
How is this question related to a problem which requires you to:
Solve f(x)=1\text{ for }x\,.​
?

To which question are you referring? I never mentioned having to solve f(x)=1
 
The problem asks to determine f-1(1)=x. The equation is equivalent to 1 =f(x), that is, 3x+1+sin(x)=1. Solve for x.

ehild
 
SammyS said:
How is this question related to a problem which requires you to:
Solve f(x)=1\text{ for }x\,.​
?

togame said:
To which question are you referring? I never mentioned having to solve f(x)=1
I'll state it more clearly.

How are the following two problems related?
Determine the value of f^{-1}(1)\,.

Solve f(x)=1\text{ for }x\,.​
 
togame said:
The exact wording for this problem:
f(x) = 3x + 1 + \sin(x) with domain [-\pi/2, \pi/2]. Without your calculator, determine the value of f^{-1}(1).

Since this is an inverse function, I was going to try to solve for the inverse function, then solve for f^{-1}(1)
While that is the general method, if you are lucky the problem is one that can be solved by recognizing it to be a special case that is easy to solve without ploughing all the way through the full general method (even if the general method were possible).

So you are being asked to find the x value (or values) that makes

3x + 1 + \sin(x) = 1

Play around with that equation to see whether you can knock it into something that speaks meaningfully to you. :smile:
 
SammyS said:
I'll state it more clearly.

How are the following two problems related?
Determine the value of f^{-1}(1)\,.

Solve f(x)=1\text{ for }x\,.​

NascentOxygen said:
While that is the general method, if you are lucky the problem is one that can be solved by recognizing it to be a special case that is easy to solve without ploughing all the way through the full general method (even if the general method were possible).

So you are being asked to find the x value (or values) that makes

3x + 1 + \sin(x) = 1

Play around with that equation to see whether you can knock it into something that speaks meaningfully to you. :smile:

Ah, I see what you guys are talking about now. Thanks for the help. Much appreciated.
 

Similar threads

Replies
15
Views
2K
Replies
10
Views
2K
Replies
3
Views
2K
Replies
3
Views
1K
Replies
15
Views
2K
Replies
14
Views
3K
Replies
7
Views
2K
Back
Top