设<img src="https://static.zxtiku.com/wangke/imgs/topic/a3e83a5784e1704a8382d00b3ed72705.png"/>连续，<img src="https://static.zxtiku.com/wangke/imgs/topic/9ad3c1a1a9006929e811fc9cbad0deb7.png"/>，且<img src="https://static.zxtiku.com/wangke/imgs/topic/09b5fcf3c5dce1b01d30b699f2c6cdcb.png"/>，则<img src="https://static.zxtiku.com/wangke/imgs/topic/c7f31b34cf56b564a44f467d84a5bf53.png"/>（）。