Find a vector equation and parametric equations for the line segment that joins p to q. p(1, −1, 7), q(7, 5, 1)
a) Vector equation r(t) = p + t(q - p)
b) Parametric equations x(t) = 1 + 6t, y(t) = -1 + 6t, z(t) = 7 - 6t
c) Vector equation r(t) = q - t(p - q)
d) Parametric equations x(t) = 1 + t(7 - 1), y(t) = -1 + t(5 + 1), z(t) = 7 - t(7 - 1)