已知2分之x 1=4分之y 3
来源:学生作业帮助网 编辑:作业帮 时间:2024/04/29 19:03:27
x=log2(y)则X1+2X2+3X3=log2(y1)+2log2(y2)+3log2(y3)=log2(y1)+log2(y2^2)+log2(y3^3)=log2(y1y2^2y3^3)=1所
分3种情况A.Ky1>y3B.K>0时,y3>y1>y2C.K=0时,y1=y2=y3=0;绘函数图象可以直观得出结论
∵y=-2/x在(负无穷,0)上是增函数∴当y1>y2>y3>0时,0>x1>x2>x3选C
v已知ax3=by3=cz3且1/x+1/y+1/z=1求证(ax2+by2+cz2)1/3=a1/3+b1/3+c1/3令ax^3=by^3=cz^3=k,则:a=k/x^3、b=k/y^3、c=k
答:抛物线y^2=4x中,x>=0,所以X1取最小值0,Y1=0点A(0,0),B(X2,Y2),C(X3,Y3)Kab=Y2/X2=4/Y2Kac=Y3/X3=4/Y3Kbc=(Y3-Y2)/(X3
X1+X2=-B/A=2X1*X2=C/A=1/2求得X1=1+根号2或者X1=1-根号2从而求出X2的值X1/X2+X2/X1=(X1*X1+X2*X2)/(X1X2)=6
x1+x2=5;x1x2=1;(1)x1/x2+x2/x1=(x1²+x2²)/(x1x2)=((x1+x2)²-2x1x2)/(x1x2)=(25-2)/1=23;(2
2的1004次方再乘xy1=2xy2=1/xy3=2xy4=1/x如此有规律的再问:为什么2的1004次方啊再答:因为y2007=2x
由已知y1,y2,y3到x1,x2,x3的变换矩阵为221315323此矩阵的逆为-7-4963-732-4所以,x1,x2,x3到y1,y2,y3的变换为y1=-7x1-4x2+9x3y2=6x1+
x1+x2=[-b+√(b²-4ac)-b-√(b²-4ac)]/(2a)=-2b/(2a)=-b/ax1x2=[-b+√(b²-4ac)][-b-√(b²-4
∵k<0,∴在反比例函数的每一分支上,y随x增大而增大,且x大于0时,y总小于0∴y1<0,y2<0,y3>0.∵x1>x2∴y1>y2∴y3>0>y1>y2答:大小关系为y2<y1<y3(这道题画图
已知点(-2,y1)(-1,y2)(1,y3)都在直线y=3分之1x+b,因为k=3分之1>0所以函数是增函数又-2
A-B=(x3+2y3-xy2)-(﹣y3+x3+2xy2)=x³+2y³-xy²+y³-x³-2xy²=3y³-3xy²
2√2-2或-2√2-2
x1+x2=-3/2x1x2=-21/x1+1/x2=(x1+x2)/x1x2=(-3/2)/(-2)=3/4x1²+x2²=(x1+x2)²-2x1x2=(-3/2)&
x1+x2=4x1x2=-1(x1+x2)^2/(1/x1+1/x2)=(x1+x2)^2*x1x2/(x1+x2)=x1x2*(x1+x2)=-4