mathematics - How can I move an object in an "infinity" or "figure 8" trajectory?

When I want to move object around point I do:

    point.x *= cosf(timer.timeElapsed);
    point.y *= sinf(timer.timeElapsed);

How to make point move on eight or infinity sign trajectory?

Answer

Some possibilities:

Lemniscate of Bernoulli

Lemniscate of Gerono

Lemniscate of Booth

Watt's curve