• Support PF! Buy your school textbooks, materials and every day products Here!

Find the value of ?

  • Thread starter mkbh_10
  • Start date
222
0
1. Homework Statement

Find the value of sin inverse (2 ) ?

2. Homework Equations



3. The Attempt at a Solution

This was a question in my final exam & i had no clue about it
 

Answers and Replies

412
2
is it a real value? what is the domain of the ArcSin function?
 
222
0
No extra information was given
 
Gib Z
Homework Helper
3,344
4
Suppose such a value, k, exists, so that [tex]\arcsin 2 = k[/tex]. Then taking sines of both sides, [tex]sin (k) = 2[/tex]. However, the sine function is bounded between -1 and 1 for all real numbers. Hence there is no real solution.
 
tiny-tim
Science Advisor
Homework Helper
25,789
249
… hyperbolic sines … !

Find the value of sin inverse (2 ) ?

This was a question in my final exam & i had no clue about it
Hi mkbh_10! Hope you passed! :smile:

Hint: cosh ix = cosx, and sinh ix = isinx.

(that's why sinh is called the hyperbolic sin!)

So sin(x + iy) = sinx cos iy + cosx sin iy = sinx coshy - i cosx sinhy;

so you needed cosx = 0, and … ? :smile:
 
222
0
Hi mkbh_10! Hope you passed! :smile:

Hint: cosh ix = cosx, and sinh ix = isinx.

(that's why sinh is called the hyperbolic sin!)

So sin(x + iy) = sinx cos iy + cosx sin iy = sinx coshy - i cosx sinhy;

so you needed cosx = 0, and … ? :smile:


But there is no hyperbolic sine function in the question ?

I am studying in DU (Delhi University ) so results will only be out in mid July . I will definitely pass but i want top marks which i will not be getting in this paper coz of my silly mistakes .
 
HallsofIvy
Science Advisor
Homework Helper
41,738
899
What course is this for? That's important. If you are studying complex numbers in the course, then there is a solution, if not, there is no solution.

And just because there is no "hyperbolic sine" in the problem doesn't mean you can't use one to solve it.
 
222
0
i have not found it anywhere in my course , thats why i am asking , i didn't study this type of question neither did our teacher taught nor does the book has this type of questions
 
222
0
i have studied complex numbers but i have no clue about it
 
tiny-tim
Science Advisor
Homework Helper
25,789
249
… really unfair … !

i have not found it anywhere in my course , thats why i am asking , i didn't study this type of question neither did our teacher taught nor does the book has this type of questions
That's really unfair! :mad:

(even if you've done things like log(-1) and log(i), sin(ix) isn't obvious, and should have been pointed out to you, IMO)

(Check the official syllabus, to see if it's on it … if it's not, complain about the exam … if it is, check with your fellow students, and make a joint request for credit for that question … will your student union help you with that?)

(btw, sin (π/2 - isinh^(-1)2) = 2)
 
222
0
this is india, nothing happens at student level , & there are 30-40 clgs in DU that have this course & who knows what teacher teaches in a particular topic
 
412
2
this is india, nothing happens at student level , & there are 30-40 clgs in DU that have this course & who knows what teacher teaches in a particular topic
share your pain bro.. share your pain.
 

Related Threads for: Find the value of ?

  • Last Post
Replies
5
Views
678
  • Last Post
Replies
4
Views
788
Replies
3
Views
4K
  • Last Post
Replies
17
Views
2K
  • Last Post
Replies
3
Views
519
  • Last Post
Replies
3
Views
426
  • Last Post
Replies
1
Views
737
  • Last Post
Replies
3
Views
891
Top