The amplitude is |-3| = 3.
The period, T, is obtained from
(2*pi)/T = 2
T = pi
From the calculator, the first positive zero is approximately x = 0.85
Algebraically:
The cos function takes a minimum of -1 and a maximum value of +1.
Therefore y can be at most -3 or +3.
This makes the amplitude = 3.
The general expression for the sinusoidal function is
y = Acos((2*pi)/T + b) + k
Therefore, find T from the equation
(2*pi)/T = 2 => T = pi.
