Results 1 to 2 of 2

Math Help - find values such that f(x) is a real number

  1. #1
    Senior Member
    Joined
    Aug 2009
    Posts
    349

    find values such that f(x) is a real number

    ok so here goes...

    let f(x) = arcsin(arcsin x). find the values of x in the interval -1< x< 1 such that f(x) is a real number. please note the less than greater than signs should be equal to as well, i don't know how to make that symbol on the computer.

    can anyone suggest some software or program that is good for making or creating math symbols. thanks in advance.

    real quick let me get back to the problem, what i basically did for this problem, was graph the sin function and the inverse of sin, and after looking at the graphs came to the conclusion that the x is defined in between the -1 and 1, or where sin (-1) and sin (1), after that the arcsin function doesn't exist. for some reason im not sure i could use that as a viable answer. is there a way i could prove this? thx
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Super Member
    earboth's Avatar
    Joined
    Jan 2006
    From
    Germany
    Posts
    5,830
    Thanks
    123
    Quote Originally Posted by slapmaxwell1 View Post
    ok so here goes...

    let f(x) = arcsin(arcsin x). find the values of x in the interval -1< x< 1 such that f(x) is a real number. please note the less than greater than signs should be equal to as well, i don't know how to make that symbol on the computer.

    can anyone suggest some software or program that is good for making or creating math symbols. thanks in advance.

    real quick let me get back to the problem, what i basically did for this problem, was graph the sin function and the inverse of sin, and after looking at the graphs came to the conclusion that the x is defined in between the -1 and 1, or where sin (-1) and sin (1), after that the arcsin function doesn't exist. for some reason im not sure i could use that as a viable answer. is there a way i could prove this? thx
    1. The arcsin-function is defined for -1\le x \le 1.

    2. Then the function

    f(x)=\arcsin(\arcsin(x)) is defined for -1 \le \arcsin(x) \le 1

    3. Use the inverse function of arcsin to solve the inequality for x:

    -1 \le \arcsin(x) \le 1~\implies~ \sin(-1) \le x \le \sin(1)
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Find the maximum values of a real constant
    Posted in the Pre-Calculus Forum
    Replies: 0
    Last Post: March 5th 2011, 03:03 PM
  2. Find the real positif number
    Posted in the Pre-Calculus Forum
    Replies: 1
    Last Post: June 6th 2010, 11:33 PM
  3. Can You find real values where f is continous?
    Posted in the Differential Geometry Forum
    Replies: 1
    Last Post: December 10th 2009, 03:16 AM
  4. Find all the real values of a?
    Posted in the Number Theory Forum
    Replies: 1
    Last Post: May 24th 2009, 01:24 AM
  5. Find all real-number solutions...
    Posted in the Algebra Forum
    Replies: 1
    Last Post: April 23rd 2008, 06:35 AM

Search Tags


/mathhelpforum @mathhelpforum