当x=时 x 3 3根号x除以根号x 1有最小值
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先要把等式化简:(12-3x)/(x^2+x-2)÷(x-2-3x/x+2)=3(4-x)/((x+2)(x-1))÷((x^2-3x-4)/(x+2))=3(4-x)/((x+2)(x-1))÷((
1.x的2006次幂乘以y的2007次幂=x的2006次幂乘以y的2006次幂乘以y因为x=√3+√2y=√3-√2(√是根号)所以x的2006次幂乘以y的2006次幂乘以y=【(√3+√2)*(√3
令x=u²,dx=2udu∫(cos√x)/√xdx=∫cos(u)/u*(2udu)=2∫cos(u)du=2sin(u)+C=2sin(√x)+C
被开方数要大于等于0,才有意义根号2x,2x≥0,x≥0才有意义根号-x,-x≥0,x≤0才有意义根号x²,无论x取何值,x²≥0,无论x为何值都有意义
题目意思不是很明确,是[(X*X-3X)/X]/[(X+3)/(2-X)]吗?那么答案是(32倍根号3-93)/39
由洛必达法则,原式=lim(x趋于无穷)(arctanx)^2/(x/√(x^2+1))=lim√(x^2+1)/x*lim(arctanx)^2=1*(π/2)^2=π^2/4
根号下大于等于0x≥0-x≥0,则x≤0同时成立所以x=0
X÷X√(1/X)=X÷(X/√X)=X*√X/X=√X.
lim(x->0)[√(1+x^2)-cosx]/sin[1/(3x)](等价代换)=lim(x->0)3x[√(1+x^2)-cosx]=0再问:好像不对啊最后答案是9再答:哦,答案错了或者你打错了
根x+根y=根5-根3..(根x+根y)(根x+根y)=(根5-根3)(根5-根3)=8-2根15=x+y+2根xy根xy=根15-根3所以x+y=8-4根15+2根3
x=√3/3(x-3)/(x+3)=(√3-9)/(√3+9)=(√3-9)^2/(-78)=(18√3-84)/78=(6√3-28)/27[(x^2-3x)/(x-2)]/[(x+3)/(2-x)
当x趋于0,分母的极限=0,所以通分得;x*(根号下(1+sinx)+根号下(cosx))/(1+sinx-cos)这是个0/0型的极限,上下求导,得:[x*(根号下(1+sinx)+根号下(cosx
3-2x>=0x+2>=0∴-2
(x^2-1)(x+1)/x^2-1除以(1+x^2+1/2x)=(x+1)*2x/(x+1)^2=2x/(x+1)=2(1+∫3)/(2+∫3)=2(1+∫3)/(2-∫3)=2∫3-2再问:(1)
√[x+2√﹙x-1﹚]-√[x-2√﹙x-1﹚]=√[﹙x-1﹚+2√﹙x-1﹚+1]-√[﹙x-1﹚-2√﹙x-1﹚+1]=√[√﹙x-1﹚+1]²-√[﹙x-1﹚-1]²=|
=根号12+根号3-根号27=2根号3+根号3-3根号3=0
可知x≥0,y≥0(x-y)/(√x+√y)-(x-2√xy+y)/(√x-√y)=(√x+√y)(√x-√y)/(√x+√y)-(√x-√y)²/(√x-√y)=(√x-√y)-(√x-√
x=4084y=1/9所以√x=2√y=1/3原式=4*(1/2)-2/3-9*y√y=2-2/3-1/3=1
代数式=(x²-4x+4)/[(2x-4)(x+2)]=(x-2)²/[2(x-2)(x+2)]=(x-2)/[2(x+2)x=√5代数式=(√5-2)/[2(√5+2)]=(√5
根号下的数是必须≥0的,所以x-2≥0x+2≥0X=0