gaokao 2015 Q6

gaokao · China · anhui-arts Conic sections Eccentricity or Asymptote Computation
6. Among the following hyperbolas, which one has asymptote equations $y = \pm 2 x$?
(A) $x ^ { 2 } - \frac { y ^ { 2 } } { 4 } = 1$
(B) $\frac { x ^ { 2 } } { 4 } - y ^ { 2 } = 1$
(C) $x ^ { 2 } - \frac { y ^ { 2 } } { 2 } = 1$
(D) $\frac { x ^ { 2 } } { 2 } - y ^ { 2 } = 1$
6. Among the following hyperbolas, which one has asymptote equations $y = \pm 2 x$?\\
(A) $x ^ { 2 } - \frac { y ^ { 2 } } { 4 } = 1$\\
(B) $\frac { x ^ { 2 } } { 4 } - y ^ { 2 } = 1$\\
(C) $x ^ { 2 } - \frac { y ^ { 2 } } { 2 } = 1$\\
(D) $\frac { x ^ { 2 } } { 2 } - y ^ { 2 } = 1$