cho duong tron tam (c) x2 + y2 - 4x + 8y -5 = 0. Viet phuong trinh duong tron di qua m (1;-3) va cat (c) tai 2 diem P,Q sao cho M la trung diem cua PQ
21) Goi duong tron (C) co tam I (\(\dfrac{1}{2}\);1) va ban kinh R = 3. Phuong trinh nao sau day la phuong trinh anh cua duong tron (C) qua phep tinh tien theo vecto \(\overrightarrow{a}=\left(\dfrac{-1}{2};3\right)\)
A. x2 + y2 -4y - 5 = 0 B. x2 + y2 - 4y + 1 = 0 C. x2 + y2 + 4y - 5 = 0 D. x2 + y2 - 4y + 5 = 0
Ta có:
I'=(1/2+(-1/2);1+3)=(0;4) => X^2 -(y-4)^2=3^2 <=> x^2 - (y^2-8y+16)=9 <=> x^2 -y^2 +8y -16-9=0. <=> x^2 - y^2 +8y - 25 =0
Chọn D
viet phuong trinh duong tron di qua m (1;-3) va cat (c) tai 2 diem P,Q sao cho m la trung diem cua PQ.
1,cho duong tron (C) : x2+ y2+2x - 4y = 0
Diem M( 4,7)
a, chung minh diem M(4,7) nam ngoai (C)
b, viet phuong trinh tiep tuyen cua (C) biet tiep tuyen qua M
2, viet pt duong tron (C)co ban kinh r=2 (C)tiep xuc Ox va co tam thuoc duong thang d : x+y - 3 = 0
3, cho duong thang denta : 3x - 4y - 31 = 0 ; M(1;7)
a, chung minh M thuoc denta
b, lap trinh duong tron (C) ban kinh r = 5 va tiep xuc duong tron denta tai M
trong mat phang toa do Oxy ,cho hinh chu nhat ABCD co phuong trinh duong thang AB:x-2y+1=0 va duong cheo BD:x-7y+14=0
a)tim toa do diem B.
b) viet phuong trinh tong quat cua duong thang BC.
c)viet phuong trinh duong tron tamBco ban kinh BIbietI(-1/5;-3/5)
1,cho duong tron (C) : x2+ y2+2x - 4y = 0
Diem M( 4,7)
a, chung minh diem M(4,7) nam ngoai (C)
b, viet phuong trinh tiep tuyen cua (C) biet tiep tuyen qua M
2, viet pt duong tron (C)co ban kinh r=2 (C)tiep xuc Ox va co tam thuoc duong thang d : x+y - 3 = 0
3, cho duong thang denta : 3x - 4y - 31 = 0 ; M(1;7)
a, chung minh M thuoc denta
b, lap trinh duong tron (C) ban kinh r = 5 va tiep xuc duong tron denta tai M
Trong mặt phẳng tọa độ oxy, cho tam giac abc vuong tai co dinh b(-3;2), duong phan giac trong goc a co phuong trinh x+y-7=0. viet phuong trinh duong tron noi tiep tam giac abc, biet dien tich tam giac abc bang 24 va a co hoanh do duong
cho duong tron tam o duong kinh AB goi I la tiep diem OA va duong tron tam S di qua A
a,chung minh duong tron tam O va duong tron tam S tiep xuc trong tai A
b,mot duong thang di qua gap duong tron tam S tai M va duogn tron tam O tai P. chung minh rang SM song song OP
Cho (o) duong kinh AB, M la 1 diem ben ngoai duong tron sao cho MA,MB cat duong tron thu tu tai EvaD. GoiH la giao diem cus AD vs BE c:
1, 4 diemM,E,H,D nam tren 1 duong tron. Xac dinh tam I cua duong tron
2., cm IO di qua trung diem IO
3, EI la tiep tuyen cuo (o)
cho duong thang Oxy, cho duong thang (d):y=2x+6 a. viet phuong trinh duong thang di qua M(3,4)va song song voi duong thang (d)
Vì (d1)//(d) nên a=2
Vậy: (d1): y=2x+b
Thay x=3 và y=4 vào (d1), ta được:
b+6=4
hay b=-2