Consider the curve r(t) = (a cos t + b sin t)i + (c cos t + d sin t)j + (e cos t + f sin t)k, where a, b, c, d, e, and f are real numbers. It can be shown that this curve lies in a plane.

Find a general expression for a nonzero vector orthogonal to the
plane containing the curve.

r(t) = (a cos t + b sin t)i + (c cos t + d sin t)j + (e cos t + f sin t)k,
where (a, c, e) × (b, d, f) ≠ 0.