Answer: Using the trigonometric definitions for any angle theta, the trigonometric functions that are undefined when x = 0 are tanθ and secθ. The trigonometric functions that are undefined when y = 0 are cotθ and cscθ. The trigonometric functions that do not depend on the value of r are tanθ and cotθ.
Step-by-step explanation:
Construct a trigonometric ratio for triangle and you will see that cot and tan are independent of the value, r.
NOTE: A ratio is undefined if the denominator is zero.
Also, from that trigonometric ratio constructed, if x=0, only tanθ and secθ become undefined. And if y=0, only cotθ and cscθ become undefined.
The attachment below shows a constructed trigonometric ratio.
