---

Lỗi biên dịch:

Main.cc: In function ‘int main()’:
Main.cc:9:8: error: invalid operands of types ‘’ and ‘int’ to binary ‘operator>>’
     sin>>a>>b>>x>>y;
     ~~~^~~
Main.cc:10:9: error: invalid operands of types ‘long double(long double) throw ()’ and ‘int’ to binary ‘operator<<’
     cosl<<(a*x)+(b*y);
     ~~~~^~~~~~~~~~~~~
Main.cc:10:16: warning: suggest parentheses around ‘+’ inside ‘<<’ [-Wparentheses]
     cosl<<(a*x)+(b*y);
           ~~~~~^~~~~~