In Excel while Calculating `=SIN(PI())` formula it returns `1.22515E-16`.If the `PI()` `Value(3.14159265358979)` is directly given like =SIN(3.14159265358979), it returns `3.23114E-15`.

Please anyone can share your opinion about how the excel calculates differently, when 'PI' and 3.14159265358979 are passed as parameter.