• 2022-06-07
    When the transmission route of the transverse feed is consistent with that of the longitudinal feed, 2f横 =f纵,
    A: 正确
    B: 错误
  • A

    内容

    • 0

      已知\( y = {f^2}(x) \),假设\( f(u) \)二阶可导,则 \( y'' \)为( ). A: \( 2{[f'(x)]^2} + 2f(x)f'(x) \) B: \( 2[f'(x)] + 2f(x)f''(x) \) C: \( 2{[f'(x)]^2} + 2f(x)f''(x) \) D: \( 2{[f'(x)]^2} + f(x)f''(x) \)

    • 1

      The content of nitrogen-free extracts in the feed can be directly determined. A: 正确 B: 错误

    • 2

      若函数$f(x)$具有二阶导数,且$y=f({{x}^{2}})$,则$y'' =$( )。 A: $f'' ({{x}^{2}})$ B: $2f'’ ({{x}^{2}})$ C: $2f’ ({{x}^{2}})+4{{x}^{2}}f’' ({{x}^{2}})$ D: $4{{x}^{2}}f’ ({{x}^{2}})+2f'' ({{x}^{2}})$

    • 3

      【填空题】If you rotate the feed rate knob clockwise, the feed rate _______________ .

    • 4

      Cutting parameters include cutting speed, feed and cutting thickness. A: 正确 B: 错误