/in/foo.c: In function 'main':
/in/foo.c:12:32: error: too many arguments to function 'sqrt'
   12 |                         x1=(-b+sqrt(delta,0.5))/(2*a);
      |                                ^~~~
In file included from /usr/include/features.h:489,
                 from /usr/include/x86_64-linux-gnu/bits/libc-header-start.h:33,
                 from /usr/include/stdio.h:27,
                 from /in/foo.c:1:
/usr/include/x86_64-linux-gnu/bits/mathcalls.h:143:1: note: declared here
  143 | __MATHCALL (sqrt,, (_Mdouble_ __x));
      | ^~~~~~~~~~
/in/foo.c:13:32: error: too many arguments to function 'sqrt'
   13 |                         x2=(-b-sqrt(delta,0.5))/(2*a);
      |                                ^~~~
/usr/include/x86_64-linux-gnu/bits/mathcalls.h:143:1: note: declared here
  143 | __MATHCALL (sqrt,, (_Mdouble_ __x));
      | ^~~~~~~~~~
/in/foo.c:20:32: warning: implicit declaration of function 'power' [-Wimplicit-function-declaration]
   20 |                         x2=(-b+power(delta,0.5))/(2*a);
      |                                ^~~~~
/in/foo.c: At top level:
/in/foo.c:24:17: error: expected identifier or '(' before 'return'
   24 |                 return 0;
      |                 ^~~~~~
/in/foo.c:25:1: error: expected identifier or '(' before '}' token
   25 | }
      | ^