nothing+on+you

雍废琼2677关于none与nothing的问题.
邹面待15758883252 ______ 你的答案错了,应该选Bnone强调数量,no one强调具体某个人,例如:How many people are there in the room? None.Who knows the answer to the question? No one.

雍废琼2677已知圆C:x^2+y^2 - 2mx - y+2m=0当m= - 1/2,若过点(0,1)的直线L与圆C相交于M,N两点,且OM垂直于ON,(O为坐标原点),求直线L的方程. -
邹面待15758883252 ______[答案] 当m=-1/2时x^2+y^2+x-y-1=0 ===>(x+1/2)^2+(y-1/2)^2=3/2 设所求直线L方程为y=kx+1 ;M(x1,y1),N(x2,y2) OM垂直于ON则(y1/x1)*(y2/x2)=-1即x1x2+y1y2=0 把y=kx+1代入x^2+y^2+x-y-1=0 化简得(1+k^2)x^2+(k+1)x-1=0 x1+x2=-(k+1)/(1+k^2) ;...

雍废琼2677解析几何,点P在椭圆PQ+PR取值范围是点P在椭圆X^2/4+Y^2/3=1上运动,Q,R分别在圆(x+1)^2+y^2=1和(x - 1)^2+y^2=1上运动,PQ+PR取值范围是 -
邹面待15758883252 ______[答案] 设F1(-1,0),F2(1,0) ,则 PF1-1≤PQ≤PF1+1 PF2-1≤PR≤PF2+1 所以 PF1+PF2-2≤PQ+PR≤PF1+PF2+2 而PF1+PF2=2a=4 所以 PQ+PR取值范围是:[2,6 ]

雍废琼2677关于英文用something+a.anything+a.nothing+a.造句 -
邹面待15758883252 ______[答案] They want to go out to see something different . Do you have anything to say There is nothing wrong with your motorbike .

雍废琼2677Nothing+Is+Something+Worth+Doing用的甚么乐器
邹面待15758883252 ______ “play sthon+乐器”表示“用乐器演奏…”. 例如:The girl often play the English song on the piano 这个小女孩常常用钢琴演奏英文歌曲

雍废琼2677设定点M( - 3,4),动点N在圆x2+y2=4上运动,以OM.ON为两边作平行四边形OMPN,求点P的轨迹方程. -
邹面待15758883252 ______[答案] 向量MP=向量ON N(x1,y1) P(x,y) x+3=x1;y-4=y1 代入,得 (x+3)^2+(y-4)^2=4 当N在直线OM上时不可行.即(±6/5,±8/5) x+3≠±6/5,x≠-9/5且x≠-21/5 综上,P的轨迹方程为 (x+3)^2+(y-4)^2=4,x≠-9/5且x≠-21/5 祝您学习...

雍废琼2677直线Ax+By+C=0与圆x^2+y^2=4.交M.N.且C^2=A^2+B^2.求向量OM*向量ON的值.O为原点. -
邹面待15758883252 ______[答案] 由题意可知原点到直线ax+by+c=0的距离是d=|c|/根号(a^2+b^2),又因为a^2+b^2=c^2,可知d=1. om=on=2,由此可得出角mon=120度, 所以om*on=2*2*sin120度=2*根号3

雍废琼2677设一次函数y=kx+b的图像经过P(3,2),它与x轴、y轴的正方向分别交于M,N两点,如果OM+ON=12,求一次函数y=kx+ -
邹面待15758883252 ______ 解:∵一次函数y=kx+b的图像经过P(3,2) ∴3k+b=2 ① 又∵y=kx+b与x轴、y轴的正方向分别交于M,N两点 ∴OM=x=-b/k,ON=b 又∵OM+ON=12 即-b/k+b=12 ② ∴联立①、②成方程组,解之得 k1=-1,b1=6 k2=-2,b2=8 ∴一次函数y=kx+b的解析式是: y=-x+6 或y=-2x+8 ∴一次函数y=kx+b图像与两坐标轴所围成的三角形面积是: 6*6÷2=18 或 8*4÷2=16

雍废琼2677已知点F是椭圆x^2/(1+a^2)+y^2=1(a>0)的右焦点,点M(m,0),N(0,n)分别是x轴,y轴上的动点且满足向量MN*向量NF=0,若点P满足向量OM=2向量ON+向量PO... -
邹面待15758883252 ______[答案] 点F是椭圆x^2/(1+a^2)+y^2=1(a>0)的右焦点,则F(a,0),向量MN*向量NF=0,则向量MN垂直向量NF,解得n方+am=0,设P(x,y),向量OM=2向量ON+向量PO,则m=-x,2n-y=0,故点P的轨迹C的方程y^2=4ax

雍废琼2677a,b在3x - y+5=0,3x - y - 13=0运动,ab中点m在x^2+y^2=8内,求m横坐标范 -
邹面待15758883252 ______[答案] A(1,-2),B(5,3) 点C在直线3X+Y-1=0上 y=1-3x C(c,1-3c) xA+xC=0 xC=c=-1 C(-1,4) k(AB)=(3+2)/(5-1)=5/4 k(CN)=-4/5 y-4=(-4/5)*(x+1) CN:4x+5y-16=0