asymptotes y = ±x. use 1 + tan2 t = sec2 t, and sec t > 0 for ??/2 <t<?/2. (b) x = et,
y = 1 ? e?t, ?ln 2 ? t ? ln 2. Answer: 1 ? 1/x ? y = 0, x > 0, the right branch of
hyperbola with vertex at at (1,0) and asymptotes y = 1, x = 0. (c) x = 2 cost, y = 3
sint, ??<t<?. Answer: x2/4 + y2/9 ? 1 = 0, ellipse. (d) x = 2 cos(2t), y = 2 sin(2t), ??
/2 ... 
