Error when using sin() function

Question

I'm trying to use sine function such as: S = sin(0.8)

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    #include <math.h>
    #include <stdint.h>
    
    float S=1;
    void main (void)
    {
        S=sin(0.5);
    }
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    #include <math.h>
    #include <stdint.h>
    
    float S=1;
    void main (void)
    {
        S=sin(0.5);
    }

But variable S come to zero after this code. Go to Debug mode and add a break point to view the change of variable, i detected that the chip went to NRF_BREAKPOINT_COND; in app_error_weak.c after run S=sin(0.5); So i determined the error come from sin() function.

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    NRF_BREAKPOINT_COND;
    // On assert, the system can only recover with a reset.
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    NRF_BREAKPOINT_COND;
    // On assert, the system can only recover with a reset.

Does anyone get the same problem?

I'm using NRF52832 with nRF5 SDK v15.0.0 on KeilC IDE, please help me. Thanks