View Compilation Error

0_0_2736765_20530.cpp: In function `int main()':
0_0_2736765_20530.cpp:12: error: `z' undeclared (first use this function)
0_0_2736765_20530.cpp:12: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_2736765_20530.cpp:13: error: `sqrt' undeclared (first use this function)