You are Here: Home >< Maths

# Inverse trig functions Watch

1. How to do something like arcsin[sin(pi/3)]. Wtf does this even mean

safe
2. (Original post by QuantumSuicide)
How to do something like arcsin[sin(pi/3)]. Wtf does this even mean

safe
You're taking the inverse of a function, so wouldn't you just be left with the initial value?

It's just isn't it?

Posted from TSR Mobile
3. (Original post by majmuh24)
You're taking the inverse of a function, so wouldn't you just be left with the initial value?

It's just isn't it?

Posted from TSR Mobile
Seems like it, but this doesn't work for something like arcsin[sin(2pi/3)]
4. (Original post by QuantumSuicide)
Seems like it, but this doesn't work for something like arcsin[sin(2pi/3)]
Arcsin only returns the principle angle.
5. How do I even go about solving these?

Posted from TSR Mobile
6. (Original post by QuantumSuicide)
How to do something like arcsin[sin(pi/3)]. Wtf does this even mean

safe
what did you get for c1 c2 s1.
What other subs do you do?
7. (Original post by QuantumSuicide)
How to do something like arcsin[sin(pi/3)]. Wtf does this even mean

safe
Well, you know what sin(pi/3) is because it's a standard angle. And you know what arcsin does to a value.

All you have to do is decide how the answer relates to pi/3 i.e. is it within the range of values for a principal angle.
8. (Original post by davros)
Well, you know what sin(pi/3) is because it's a standard angle. And you know what arcsin does to a value.

All you have to do is decide how the answer relates to pi/3 i.e. is it within the range of values for a principal angle.
I'm just unsure about how to draw the quadrants, where the angles go etc for these inverse trig expressions

Posted from TSR Mobile
9. (Original post by QuantumSuicide)
I'm just unsure about how to draw the quadrants, where the angles go etc for these inverse trig expressions

Posted from TSR Mobile
Start by writing down what range of angles can be returned by arcsin.
10. (Original post by davros)
Start by writing down what range of angles can be returned by arcsin.
So should i just bang arcsin(sin(pi/3)) in my calculator? I get pi/3

Posted from TSR Mobile
11. (Original post by QuantumSuicide)
So should i just bang arcsin(sin(pi/3)) in my calculator? I get pi/3

Posted from TSR Mobile
Well that's certainly one way of answering the question
12. (Original post by davros)
Well that's certainly one way of answering the question

I'm really not understanding this lol. If anyone could take me through an example with the quadrant method, that would be great.

How would I do arctan(root3)

Posted from TSR Mobile
13. (Original post by QuantumSuicide)

I'm really not understanding this lol. If anyone could take me through an example with the quadrant method, that would be great.

How would I do arctan(root3)

Posted from TSR Mobile
I don't get why you're trying to confuse yourself?
Youre aware that arcsin(sin(X)) = X? Where does the quadrant method come into this at all?
14. (Original post by lmorgan95)
I don't get why you're trying to confuse yourself?
Youre aware that arcsin(sin(X)) = X? Where does the quadrant method come into this at all?
Arcsin(x) only returns the principal value.

Posted from TSR Mobile
15. (Original post by majmuh24)
Arcsin(x) only returns the principal value.

Posted from TSR Mobile
What value is he trying to get to though? You can get to the other values from the principle.
Oh right so is he asking for an explanation of how to get to the secondary+ values?
16. (Original post by lmorgan95)
What value is he trying to get to though? You can get to the other values from the principle.
Oh right so is he asking for an explanation of how to get to the secondary+ values?
Yeah, but if you take values outside the range of arcsin(x), arcsin(sin(x)) doesn't just give you x.

Posted from TSR Mobile
17. (Original post by QuantumSuicide)

I'm really not understanding this lol. If anyone could take me through an example with the quadrant method, that would be great.

How would I do arctan(root3)

Posted from TSR Mobile
Let

then

So

THe angle for which the tan gent is root(3) is degree 60

so

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: April 18, 2014
Today on TSR

### Should I hide my grades on UCAS?

I don't want Oxford to know I only got an A...

### He wants to drop out of Cambridge?

Discussions on TSR

• Latest
Poll
Useful resources

### Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

### How to use LaTex

Writing equations the easy way

### Study habits of A* students

Top tips from students who have already aced their exams