(start off array l Rightarrow sin Acos C + sin Ccos A = 2cos Asin C Leftrightarrow sin Acos C = cos Asin C;(*)end array )+ D?ng toán 2.two Vi?t ph??ng trình ???ng th?ng ?i qua m?t ?i?m vuông góc ho?c tune track v?i ???ng th?ng cho tr??c.T?t C?Th? D?c L?p 10Th? D?c L?p 11Th? D?c L?p twelfth? D?c L?p sixth? D?c L?p 7Th? D?c L?p 8Th? D?c L?p 9T?t