View Compilation Error

0_0_11557082_29271.cpp: In function `int main()':
0_0_11557082_29271.cpp:30: error: `sqrt' undeclared (first use this function)
0_0_11557082_29271.cpp:30: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_11557082_29271.cpp:56: error: expected primary-expression before "long"
0_0_11557082_29271.cpp:56: error: expected `;' before "long"