Thread: double pow not working?

  1. #1
    Registered User
    Join Date
    Apr 2006

    double pow not working?

    printf("Approximate cos(%d) = %lf", xdeg, 1-(double pow(radians, 2)/2) + (double pow(radians, 4)/24);
    This is just a part of it, but everything seems to be right except for an error I get.

    test.c:32: error: parse error before "pow"
    test.c:32: error: parse error before ';' token
    Anyone know if this is a very simple mistake or is something wrong with my whole program?

  2. #2
    Registered User joed's Avatar
    Join Date
    Mar 2004
    Double is the return type, you don't need it in the program. Just do pow(a, b).

  3. #3
    Lurking whiteflags's Avatar
    Join Date
    Apr 2006
    United States
    You aren't supposed to specify a return value when you make a function call. C finds the correct function to use by name and parameter list.
    PHP Code:
    printf("Approximate cos(%d) = %lf"xdeg1pow(radians2)/pow(radians4)/24); 
    That will run fine.

    The exception here is when you want to typecast the return value, where you would have syntax issues:
    PHP Code:
     printf("Approximate cos(%d) = %lf"xdeg1- (double) pow(radians2)/+  (double) pow(radians4)/24); 
    This runs fine too, but you should only do this when the function the compiler will call will not return the necessary return type.
    Last edited by whiteflags; 05-01-2006 at 05:40 PM.

  4. #4
    Frequently Quite Prolix dwks's Avatar
    Join Date
    Apr 2005
    Your second error was due to a missing ')'.

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