For an equation y = a tan[b(x+c)], the period is equal to 2*pi/b, while the phase shift is c.
This equation can be rewritten as:
f(x) = 3 tan [4(x + pi/4)]
In this case, b = 4, c = pi/4
Then the period = 2*pi/b = pi/2.
The phase shift = pi/4 (to the left).
