So the derivative of negative six t is negative six, the derivative of constant is just zero. So this thing, the second derivative is always negative. So we are always, always concave, concave downward, downward. And so by the second derivative test, at t equals two, well at t equals two, our second derivative of our acceleration function is going to be negative. And so we know that this is our maximum value, or our max at t is equal to two. So at what value of t does the particle obtain its maximum acceleration? At t is equal to, at t is equal to two.