求当x=0时,y=xsin1 x的极限-搜答案-智慧作业帮

Dimax,yAsIntegerPrivateSubCommand1_Click()x=Text1.TextIfx>0Theny=4*x+1Else:y=3*x+1EndIfText2.Text=yE

∵y+2与x-3成反比例函数，∴y+2=kx−3，∵当x=2时，y=-3，∴k=（-3+2）×（2-3）=1，∴y+2=1x−3，y=1x−3-2．∴当x=0时y=-73．

为方便打字,我用m代替x对y的导数d/dy*（y-x-lnx）=01-m-m/x=0所以m=x/（1+x）,事实上你先对y求x的导,再取倒数也可以,殊途同归y=1,x=1,所以m=0.5

x+y/x-y=1/2取倒数x-y/x+y=2所以x-y/x+y-2x+2y/x-y=x-y/x+y-2(x+y/x-y)=2-2×1/2=2-1=1

y'=p,y''=dp/dx,xp'+xp^2-p=0p'=(-xp^2+p)/x,p'-1/x*p=-p^2伯努利方程,换元求出p,再求y

原式=1/2×2x-y/x+y+2x-y/6x-3y=1/2+1/3=5/6

(2x-y)/(x+y)=3所以(x+y)/(2x-y)=1/3原式=1/2*(2x-y)/(x+y)+1/3*(x+y)/(2x-y)=3/2+1/9=29/18

15

当x=1时,y=0当x=-3时,y=0即x=1或-3是方程ax²+bx+c=0的两根即a（x-1）（x+3）=0即y=a（x-1）（x+3）=a（x²+2x-3）又当x=2时,y=

y=(x2+2x+5)/x=(x+2+5/x)≥2+2√(x*5/x)=2+2√5最小值=2+2√5

用等价无穷小替换和洛必达法则.原式=lim(x→0)(sinx-x)/x^3=lim(x→0)(cosx-1)/(3x^2)=lim(x→0)(-sinx)/(6x)=lim(x→0)(-cosx)/

均值不等式.y=x/2+x/2+4/(x^2)当x/2=x/2=4/x^2,即x=2时,y最小,为3.

y = 2x / (x^2 - 1)化为 y = 2 / (x - 1

y=-2x+52x=5-yx=(5-y)/2-2x+5>02-5>-2x>-53/2

题目应该少了条件,应附加X,Y是一次函数关系则k=(100-0)/(20-4)=25/4且k=25/4=（Y-0)/(5-4)得Y=25/4

2x-y\x+y=32x-y=3(x+y)2x-y=3x+3y3x-2x=-y-3yx=-4y2x-y/2x+2y+x+y/6x-3y=(-8y-y)/(-8y+2y)+(-4y+y)/(-24y-3

由三角函数的定义可知：|sin1x|＜1，由函数极限的性质可知：limx→0x=0故有：limx→0xsin1x=0故选择：B．

y与2x+1成反正比=>y(2x+1)=k定值(1,2)代入=>2*3=k=6(0,y)代入=>y*1=6=>y=6...ansorA,B成反正比=>A1:A2=B2:B1=>2:y=(2*0+1):

原式=(x-y)/x/((x^2-2xy+y^2)/x)=(x-y)/x乘以(x/(x^2-2xy+y^2))=(x-y)/x乘以(x/(x-y)^2)=1/(x-y)当x=2008,y=2009原式

再答：6028再问：x和y呢？再答：再问：谢！赏！