View Compilation Error

622483_0_0_19067.cpp: In function `int main()':
622483_0_0_19067.cpp:7: error: `sqrt' undeclared (first use this function)
622483_0_0_19067.cpp:7: error: (Each undeclared identifier is reported only once for each function it appears in.)
622483_0_0_19067.cpp:9: error: `falg' undeclared (first use this function)