The focus of hyperbola 9x & # 178; - 4Y & # 178; = 1 is

The focus of hyperbola 9x & # 178; - 4Y & # 178; = 1 is

The focus is on the x-axis, where a & # 178; = 1 / 9, B & # 178; = 1 / 4, because C & # 178; = A & # 178; + B & # 178;, then C = 13 / 36. The focus is (- 13 / 36,0), (13 / 36,0)