Answer:
Tan.
Step-by-step explanation:
First way;
Tan (90-θ )=Cot θ Tan (90+θ )= -Cot θ
1st explanation, QUOTATIONS!
"tan90∘ is undefined because you can't divide 1 by nothing. Nothing multiplied by 0 will give an answer of 1 , so the answer is undefined."
2nd explanation, QUOTATIONS!
"That's undefined because as you approach 90° from either direction, tan approaches positive or negative infinity. cot(90°) hence approaches 1/infinity (either positive or negative) which is just 0."
