• 2022-06-07
    椭球面[img=145x26]18030b0438b6509.png[/img]在点[img=55x25]18030b04419b3f5.png[/img]处的法线方程为( )
    A: [img=176x43]18030b044a00b1d.png[/img]
    B: [img=152x43]18030b04520b918.png[/img]
    C: [img=145x43]18030b045abcd46.png[/img]
    D: [img=152x43]18030b046215d30.png[/img]
  • B

    举一反三

    内容

    • 0

      下列等值式不正确的是: 未知类型:{'options': ['', '┐([img=10x19]17de6020f4c375c.png[/img]x)A [img=18x11]17de60210176264.png[/img]([img=10x19]17de60210dea9b9.png[/img] x)┐A', '(∃x)(A(x)∧B(x))[img=18x11]17de60210176264.png[/img] (∃x)A(x)∧(∃ x)B(x)', '(∀x)(∀y)(A(x)→B(y))[img=18x11]17de60210176264.png[/img] (∀x)A(x)→(∀y)B(y)'], 'type': 102}

    • 1

      考虑二元函数的下面四条性质,则有( )(1)f(x,y)在点[img=52x25]1803d3469e57b15.png[/img]处连续 (2)f(x,y)在点[img=52x25]1803d3469e57b15.png[/img]处两个偏导数连续(3)f(x,y)在点[img=52x25]1803d3469e57b15.png[/img]处可微 (4)f(x,y)在点[img=52x25]1803d3469e57b15.png[/img]处两个偏导数存在 A: [img=125x25]1803d346c03fe8a.png[/img] B: [img=125x25]1803d346c8da475.png[/img] C: [img=125x25]1803d346d101a9e.png[/img] D: [img=125x25]1803d346d9681c2.png[/img]

    • 2

      考虑二元函数的下面四条性质,则有( )(1)f(x,y)在点[img=52x25]1803d33f049b721.png[/img]处连续 (2)f(x,y)在点[img=52x25]1803d33f049b721.png[/img]处两个偏导数连续(3)f(x,y)在点[img=52x25]1803d33f049b721.png[/img]处可微 (4)f(x,y)在点[img=52x25]1803d33f049b721.png[/img]处两个偏导数存在 A: [img=125x25]1803d33f258c65d.png[/img] B: [img=125x25]1803d33f2f5d801.png[/img] C: [img=125x25]1803d33f3820bdb.png[/img] D: [img=125x25]1803d33f40873ef.png[/img]

    • 3

      令F(x):x是有理数,G(x):x是实数。将命题“所有的有理数都是实数,但有的有实数不是有理数”符号化为() 未知类型:{'options': ['17e0a83a4157352.jpgx(F(x)∧G(x))∧[img=8x14]17e0a83a35505d4.jpg[/img]x(G(x)[img=14x9]17e0a73094b5dcf.jpg[/img][img=10x11]17e0a839b915354.jpg[/img]F(x))', ' [img=8x14]17e0a83a4157352.jpg[/img]x(F(x)[img=14x9]17e0a73094b5dcf.jpg[/img]G(x))∧[img=8x14]17e0a83a35505d4.jpg[/img]x(G(x)∧[img=10x11]17e0a839b915354.jpg[/img]F(x))', ' [img=8x14]17e0a83a4157352.jpg[/img]x(F(x)∧G(x))∧[img=8x14]17e0a83a35505d4.jpg[/img]x(G(x)∧[img=10x11]17e0a839b915354.jpg[/img]F(x))', ' [img=8x14]17e0a83a4157352.jpg[/img]x(F(x)[img=14x9]17e0a73094b5dcf.jpg[/img]G(x))∧[img=8x14]17e0a83a35505d4.jpg[/img]x(G(x)[img=14x9]17e0a73094b5dcf.jpg[/img][img=10x11]17e0a839b915354.jpg[/img]F(x))'], 'type': 102}

    • 4

      1.设随机变量X的密度为[img=186x61]18034ea953ec9dd.png[/img]则常数A=________,概率[img=146x25]18034ea95d30d08.png[/img]__________. A: A=2,P(X>1|X<2)=[img=39x24]18034ea9659b618.png[/img] B: A=-2,P(X>1|X<2)=[img=39x24]18034ea9659b618.png[/img] C: A=2,P(X>1|X<2)=[img=47x44]18034ea9768a8c2.png[/img] D: A=-2,P(X>1|X<2)=[img=47x44]18034ea9768a8c2.png[/img]