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