a+packet+of+biscuit
@都紫1850：a bag of 和a packet of 怎么用 -
靳殷19249619883…… a bag of 一包 a big bag of ice一大包冰 a large bag of popcorn一大袋爆米花 Eg.The King was pleased with his answer and gave the doctor a bag of gold.国王对他的回答很满意,并且给了医生一包金子.a packet of一捆 一包 一盒 a large packet of...
@都紫1850：a packet of sweets 作主语 谓语动词用单数还是复数 -
靳殷19249619883…… a packet of 名词复数作主语时,谓语动词通常用复数,主要是中心词的问题.a packet of ns 中后面名词是中心词,如: There are a packet a list of all the ingredients on the label. 标签上面有一个成分表.(《牛津中阶英语词典》) The following ...
@都紫1850：there +be动词 a packet of sweets.这里的be 动词是is还是are? -
靳殷19249619883…… 用is 因为后面是“a packet”(一包糖),是单数
@都紫1850：a ( )of cheese A.bit B.bar c.block D.packet 解释一下 ... -
靳殷19249619883…… C,block,是块的意思,cheese 是奶酪,而 packet是包,A和B不能和介词搭配
@都紫1850：a packet of ( ? ) -
靳殷19249619883…… a pair of一双,一副 如a pair of shoes a loaf of一条,一块a loaf of bread a packet of一包,一袋a packet rice a comb of一梳a comb of sheep
@都紫1850：一、There be句型填空 1.There - - - a packet of sweets. 2.T -
靳殷19249619883…… 一、There be句型填空 1.There (is) a packet of sweets. 2.There (are) two pancakes,of sweets. 3.There (are) bars of chocolate. 4.(ls) there a bott|e water? There be(there is+单数名词或不可数名词/there are+可数名词复数)在使用时,要遵循就近原则.
@都紫1850：设z1是虚数,z2=z1+1/z1是实数,且 - 1小于等于z2小于等于1,(1)求z1的绝对值(2)z1的实部的取值范围 -
靳殷19249619883…… 设:z1=a+bi,则:z2=(z1)+(1/z1)={a+[a/(a²+b²)]}+{b-[b/(a²+b²)]}i是实数,则:虚部b-[b/(a²+b²)]=0,得:b=0或a²+b²=1【若b=0,则z1不是虚数,则b=0舍去】,所以1、|z1|=√(a²+b²)=1;2、-1≤z2≤1,则:-1≤a+[a/(a²+b²)]≤1,即:-1≤a+a≤1,则-(1/2)≤a≤(1/2)
@都紫1850：tanx设a,b为实数,若复数1+2i/a+bi=1+i,则a,b等于多少? -
靳殷19249619883…… (1+2i)/(a+bi)=1+i a+bi=(1+2i)/(1+i)=3/2+i/2 a=3/2 b=1/2
@都紫1850：谁知道 虚数的乘法除法公式?(a+bi)*(c+di)=?(a+bi)÷(c+di)=? - 作业帮
靳殷19249619883…… [答案] (a+bi)*(c+di) =ac+adi+bci+bd*i^2 =(ac-bd)+(ad+bc)i (a+bi)÷(c+di) =(a+bi)(c-di)÷[(c+di)(c-di)] =(ac-adi+bci-bdi^2)÷(c^2-d^2i^2) =[(ac+bd)+(bc-ad)i]/(c^2+d^2)
@都紫1850：求复数z,z+5/z是实数.z+3的实部和虚部互为相反数 -
靳殷19249619883…… b的值; 即a^2+b^2=5(1);(a^2+b^2)=0,那么有b-5b/z=a+bi+5/(a+bi)=a+bi+5(a-bi)/(a^2+b^2),由于它是实数设z=a+bi,则z+5/ z+3=a+3+bi,则有(a+3)b=1(2); 由(1)(2)联立方程即可算出a
靳殷19249619883…… a bag of 一包 a big bag of ice一大包冰 a large bag of popcorn一大袋爆米花 Eg.The King was pleased with his answer and gave the doctor a bag of gold.国王对他的回答很满意,并且给了医生一包金子.a packet of一捆 一包 一盒 a large packet of...
@都紫1850：a packet of sweets 作主语 谓语动词用单数还是复数 -
靳殷19249619883…… a packet of 名词复数作主语时,谓语动词通常用复数,主要是中心词的问题.a packet of ns 中后面名词是中心词,如: There are a packet a list of all the ingredients on the label. 标签上面有一个成分表.(《牛津中阶英语词典》) The following ...
@都紫1850：there +be动词 a packet of sweets.这里的be 动词是is还是are? -
靳殷19249619883…… 用is 因为后面是“a packet”(一包糖),是单数
@都紫1850：a ( )of cheese A.bit B.bar c.block D.packet 解释一下 ... -
靳殷19249619883…… C,block,是块的意思,cheese 是奶酪,而 packet是包,A和B不能和介词搭配
@都紫1850：a packet of ( ? ) -
靳殷19249619883…… a pair of一双,一副 如a pair of shoes a loaf of一条,一块a loaf of bread a packet of一包,一袋a packet rice a comb of一梳a comb of sheep
@都紫1850：一、There be句型填空 1.There - - - a packet of sweets. 2.T -
靳殷19249619883…… 一、There be句型填空 1.There (is) a packet of sweets. 2.There (are) two pancakes,of sweets. 3.There (are) bars of chocolate. 4.(ls) there a bott|e water? There be(there is+单数名词或不可数名词/there are+可数名词复数)在使用时,要遵循就近原则.
@都紫1850：设z1是虚数,z2=z1+1/z1是实数,且 - 1小于等于z2小于等于1,(1)求z1的绝对值(2)z1的实部的取值范围 -
靳殷19249619883…… 设:z1=a+bi,则:z2=(z1)+(1/z1)={a+[a/(a²+b²)]}+{b-[b/(a²+b²)]}i是实数,则:虚部b-[b/(a²+b²)]=0,得:b=0或a²+b²=1【若b=0,则z1不是虚数,则b=0舍去】,所以1、|z1|=√(a²+b²)=1;2、-1≤z2≤1,则:-1≤a+[a/(a²+b²)]≤1,即:-1≤a+a≤1,则-(1/2)≤a≤(1/2)
@都紫1850：tanx设a,b为实数,若复数1+2i/a+bi=1+i,则a,b等于多少? -
靳殷19249619883…… (1+2i)/(a+bi)=1+i a+bi=(1+2i)/(1+i)=3/2+i/2 a=3/2 b=1/2
@都紫1850：谁知道 虚数的乘法除法公式?(a+bi)*(c+di)=?(a+bi)÷(c+di)=? - 作业帮
靳殷19249619883…… [答案] (a+bi)*(c+di) =ac+adi+bci+bd*i^2 =(ac-bd)+(ad+bc)i (a+bi)÷(c+di) =(a+bi)(c-di)÷[(c+di)(c-di)] =(ac-adi+bci-bdi^2)÷(c^2-d^2i^2) =[(ac+bd)+(bc-ad)i]/(c^2+d^2)
@都紫1850：求复数z,z+5/z是实数.z+3的实部和虚部互为相反数 -
靳殷19249619883…… b的值; 即a^2+b^2=5(1);(a^2+b^2)=0,那么有b-5b/z=a+bi+5/(a+bi)=a+bi+5(a-bi)/(a^2+b^2),由于它是实数设z=a+bi,则z+5/ z+3=a+3+bi,则有(a+3)b=1(2); 由(1)(2)联立方程即可算出a
