CMR: duong thang (d) : y=(m-2)x-3m+4 luon di qua mot diem co dinh
Cho (P): y=x^2/2 va duong thang (d): y=mx+1/2 a) Ve (P) b) CM: voi moi m duong thang (d) luon di qua mot diem co dinh c) CM: voi moi m (d) luon cat (P) tai hai diem phan biet
cho hai duong thang : (d1) : y = 4mx -(m+5) (d2): y =(3m^2 +1)x + (m^2 +9) a,voi gia tri naocua m thi (d1)//(d2) , b,voi gia tri nao cua m thi (d1) cat (d2) tim toa do giao diem khi m =2 , c, C /m rang khi m thay doi thi duong thang (d1) luon di qua diem co dinh A ,(d2) d qua diem co di B .Tinh AB ?
cho duong thang (d) : y=mx +2m -1.a) CMR (d) luon luon di qua 1 diem co dinh .b) xac dinh m de khoang cach tu O den (d) lon nhat
Cho tam giac ABC. Tren tia BA lay mot diem M, tren tia CA lay mot diem N sao cho BM+CN=BC. CMR duong trung truc cua MN luon di qua mot diem co dinh
M la mot diem bat ki tren doan thang AB. Ve ve mot phia canh cua AB cac hinh vuong AMCD, BMEF.
a, Chung minh rang AE vuong goc BC.
b, Goi H la giao diem cua AE va BC. Chung minh rang ba diem D,H,F thang hang.
c, Chung minh rang duong thang DF luon luon di qua 1 diem co dinh khi diem M chuyen dong tren doan thang AB co dinh
Diện tích toàn phần của khối nhựa hình lập phương là:
10 x 10 x 6 = 600 (cm2)
Cạnh khối gỗ hình lập phương là:
10 : 2 = 5 (cm)
Diện tích toàn phần của khối gỗ hình lập phương là:
5 x 5 x 6 = 150 (cm2)
Diện tích toàn phần của khối nhựa gấp diện tích toàn phần của khối gấp số lần là:
600 : 150 = 4 (lần)
Cau 5: Trong cac khang dinh sau, khang dinh nao dung, khang dinh nao sai?
1.Ba diem phan biet la ba diem thang hang.
2.Voi ba diem phan biet luon co hai diem nam ve cung phia doi voi diem con lai.
3.Voi ba diem thang hang phan biet luon co hai diem nam khac phia voi diem con lai.
4.Voi ba diem A,B,C thang hang thi diem B luon nam giua hai diem A,C.
5.Co mot va chi mot duong thang di qua hai diem (phan biet) cho truoc.
6.Hai duong thang phan biet thi song song voi nhau.
7.Hai tia chung goc thi cung nam tren mot duong thang.
8.Hai tia chung goc thi doi nhau
9.Neu diem M nam giua diem A,B thi no la trung diem cua doan thang AB.
10.Neu MA=MB thi M la trung diem cua doan thang AB.
11.Neu MA+MB= AB va MA=MB thi M la trung diem cua doan thang AB.
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cho (O;R) duonh kinh AB va diem M di dong tren not nua duong tron sao cho cung MA nho hom hoac bang cung MA .Ve vao trong duong tron hinh vuong AMCD .Goi E la giao diem thu hai cua duong thang MD voi (O),F la giao diem cua hai duong thang CS va BE .CMR
a, Duong thang MD luon di qua mot diem co dinh
b, tu giac ADEF la tu giac noi tiep
c, đường tròn ngoại tiếp tam giác ABC luôn đi qua tâm của đường tròn nội tiếp tam giác MAB
Giúp mình với!
cho tam giac ABC noi tiep duong tron tam O, mot diem I chuyen dong tren cung BC khong chua diem A(I khac B,C).Duong thang vuong goc voi IB tai I cat duong thang AC tai E, duong thang vuong goc voi IC cat duong thang AB tai F.Chung minh rang duong thang EF luon di qua 1 diem co dinh
cho tam giac ABC,AC>AB,cac diem D va E theo thu tu di chuyen tren cac canhAB va AC,BD=CE.CMR: cac duong trung truc cua DE luon di qua mot diem co dinh