From trigonometry we know that:
if 
then,
(where
is an integer)
This can be rewritten in degrees as:
.............(Equation 1)
Now, in our case, 
Therefore, (Equation 1) can be written as:
..........(Equation 2)
Now, to find the correct options all that we have to do is replace n by relevant integers and find the values of
that match.
For n=2, (Equation 2) gives us:
.
Thus, 
Now, we know that: 
Let n=-1, then:

Thus, 
Likewise, 
Only the last option
will never match
because no integral value of
will ever give 
Thus the last option is the correct option.
Answer: Should be -5
Step-by-step explanation:
Answer:
20
Step-by-step explanation:
420-400=20
6
1. A, b, c
2. A, b, d
3. A, b, e
4. C, a, b
5. D, a, b
6. E, a, b
Hope I helped!
Ion know I’m just tryna ask a question