Answer
$4, -2 \sqrt 2, 0, 2 \sqrt 2, -4, 2 \sqrt 2$
Work Step by Step
Given $y(t) = 4 \cos (3 \pi t)$
The question asks for y(t) for the values of t = 0, 0.25, 0.50, 0.75, 1.00, and 1.25
Thus substitute those t values and find y(t)
$y(t) = 4 \cos (3 \pi (0)) = 4(1) = 4$
$y(t) = 4 \cos (3 \pi (0.25)) = 4(\frac{-\sqrt 2}{2}) = -2 \sqrt 2$
$y(t) = 4 \cos (3 \pi (0.5)) = 4(0) = 0$
$y(t) = 4 \cos (3 \pi (0.75)) = 4(\frac{\sqrt 2}{2}) = 2\sqrt 2$
$y(t) = 4 \cos (3 \pi (1)) = 4(-1) = -4$
$y(t) = 4 \cos (3 \pi (1.25)) = 4(\frac{\sqrt 2}{2}) = 2\sqrt 2$
