None of these. All of these functions are defined as ratio of trigonometric functions.
Trigonometric functions have infinite zeroes, so when you put them in the denominator, they lead to infinitely many points of ill-definition.
Specifically, we have:

which is undefined at


which is undefined at


which is undefined at


which is undefined at

Answer:
Sec y = q/r
Step-by-step explanation:
Sin y = 7/q
tan y = 7/r
Mathematically cos y = sin y/tan y
But sec y = 1/cos y
So therefore sec y = tan y/sin y
So that would be ;
7/r divided by 7/q
= 7/r * q/7
= q/r
Answer:
6
-7
Step-by-step explanation:
simplyifying this we get
1+5i-8+i
= 6i-7
I am assuming the i you are talking about here is the sqrt of negative one so that would be 6
-7