y=1/3x2-2等于多少-搜答案-智慧作业帮

令t=x-1/x,所以有f(t)=t平方+2,所以有f(3)=11

A=〔0,4〕B=〔-8,0〕A∩B=空集CR（A∩B）=R

y'=[3(x^2+x+2)-3x(2x+1)]/(x^2+x+2)^2=(2-x^2)/(x^2+x+2)^2,因为0

y'=[3(x^2+x+2)-3x(2x+1)]/(x^2+x+2)^2=(2-x^2)/(x^2+x+2)^2,因为0

x=(1-2y^2)/3;y=正负2分之1乘以根号2（1-3x）.

(y+1)(y-2)等于多少,

-10根号a再问：过程再答：对不对啊ax=5/xx平方=5/a求出x1x2y1y2,带入4x1y2-2x2y1算出

1/2(y-3)+3(y+2)=1,1/2y－3／2＋3y＋6＝1,2y－3＋6y＋12＝2,8y＋9＝2,8y＝9－2,8y＝7,y＝8／7.

5y=1×2×3×4×5(4y+8y)÷5y=(1×2×3×4+1×2×3×4×5×6×7×8）/（1×2×3×4×5）=（1+5×6×7×8）/5=1681/5

a=2,(a-1)x2+3x-2=0是一元二次方程△=3×3-4×(a-1)×2≥0得出a=1或a=2,(a-1)x2+3x-2=0是一元二次方程,a-1不等于0,所以a只能是2

y=x2+3x+1/4,(-1

1/1x2+1/2x3+1/3x4...+1/2006x2007=(1-1/2)+(1/2-1/3)+(1/3-1/4)+(1/4-1/5)+(1/5-1/6)+.+(1/2006-1/2007)=1

令1/2x2-x+2/3=x化简得3x^2-12x+4=0则a,b为其两个不等实根.解得a=6-2根6/3b=6+2根6/3再问：能再详细点么？？为啥要令y=x?再答：根据题意因为当x大于等于a小于等

1.（1）当x=2,y=2+1=3y=2^2=4y=-2+2=0当x=-0.5,y=-0.5+1=0.5y=(-0.5)^2=0.25y=-0.5+2=1.5当x=-2,y=-2+1=-1y=(-2)

解先对y求导y'=2x+2∴y‘=2×1+2=4

1.3y=3x2+ax+4y=(?3x+2)?=3x?+4?3+4所以,a=4?32.a=16b=35因为,x=-b/2a=a/4=4所以,a=16因为,y=-2x2+16x-b把(4,-3)带入b=

X1,X2为方程X^2+3X+1=0的两实根x1^2=-1-3x1x1+x2=-3x1*x2=1X1^3+8X2+20=x1(x1^2)+8x2+20=x1(-1-3x1)+8x2+20=-x1-3x

x=8/3y=15/4就是这个了...

x=1,y=-1

(3y+5)/(3y-6)=1/2+(5y-4)/(2y-4)(3y+5)/(3y-6)-(5y-4)/(2y-4)=1/2(3y+5)/{3(y-2)}-(5y-4)/{2(y-2)}=1/2{2(