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:
x=64
Step-by-step explanation:
Both the semicircle that says 180, and the right angle sign in the image serve to support the idea that all parts of the figure equal 90
Therefore, it is safe to say that you need to subtract 26 from 90 in order to solve for x.
90-26 = 64
Answer:
x<8
Step-by-step explanation:
x+7<15
x<15-7
x<8

Answer:
y=3x+2
Step-by-step explanation:
slope = rise over run = y/x
A (-1,3) slope = 3/-1 = -3
B (1,2) slope = 2/1 = 2
C (-3,-1) slope = -1/-3 = 1/3
2 lines need to be negative reciprocals in order to be a right triangle
negative reciprocal of -3 is 1/3
so this is a right triangle