Cot(Ф)=-3
Ф=arccot(-3)
or
Ф=the inverse cotangent of -3
or
Ф=cot^-1(-3)
Answer:

Step-by-step explanation:
First, we gather the data:
The model is a single
landing strip with 
This based on the assumption that service times are exponential.
Then, we must find the maximum rate such that 
Using the
table, we find that:

if and only if

=
Y intercept (x = 0)
4(0)+3y=12
3y = 12
y = 12/3
y = 4
X intercept (y = 0)
4x+3(0)=12
4x = 12
x = 12/4
x = 3
R/ The intercept with x is (3,0) and with y (0,4)
Either factor in paren can be equal 0
so either q=-2
or q=-3/4