I would say c or d. but since its multiple choice, its ok to guess sometimes.
Irrational due to the negative sign
That would be tan
(1-cos)(1+cos)=1-cos² which equals to sin²
√sin²/cos²= sin/cos which equals to tan
Answer:

Step-by-step explanation:

→ Expand brackets

→ Add 8 to both sides to collect the whole numbers

→ Add -4m to both sides to collect the m terms

→ Divide both sides by -10 to isolate m
