设 [tex=7.0x1.357]ThFQvE3ZD3oSJrz0B75y1ycDpva7a7h5V21Cuky/ggY=[/tex] 具有二阶连续导数, 证明 [tex=7.286x1.357]NovbxKl63Ey/milqTcbe/xfB3rUobd/5Vz5f+mYtvItFsqZ+ixHHHfrVux70AlZBNO4uEE8HE8cuVRxylzAXow==[/tex] .
设 [tex=7.0x1.357]ThFQvE3ZD3oSJrz0B75y1ycDpva7a7h5V21Cuky/ggY=[/tex] 具有二阶连续导数, 证明 [tex=7.286x1.357]NovbxKl63Ey/milqTcbe/xfB3rUobd/5Vz5f+mYtvItFsqZ+ixHHHfrVux70AlZBNO4uEE8HE8cuVRxylzAXow==[/tex] .
1