i
cludestdiohi
cludemathhi
cludestdlibhdefi
eprecisio
pow106根的精度doublefdoublex定义f函数，求fxx3x1的值retur
xxxx1voidDichotomy二分法doublex2x1x上届，下届，根doublefx2fx1fx上届、下届、根对应的函数值pri
tf