Step-by-step explanation:

The binomial theorem states that for some a,b∈R and some k ∈Z+ ,
(a+b)k=∑n=0k(kn)ak−nbn.
The binomial series allows us to use the binomial theorem for instances when k is not a positive integer. The binomial series applies to a given function f(x)=(1+x)k for any k∈R with the condition that |x|<1 . It is stated as follows:
(1+x)k=∑n=0∞(kn)xn .
Note that the binomial theorem produces a finite sum and the binomial series produces an infinite sum.
Answer:I think the pair that is perpendicular is
Y=2/3x
1.180-(57+36)=87 degree
2.180-39=141
141/2=70.5 degrees each