Answer:
The answer is cos²Ф ⇒ first answer
Step-by-step explanation:
* Lets talk about the trigonometry functions
- sin²Ф + cos²Ф=1 ⇒ subtract cos²Ф from each side
∴ sin²Ф = 1 - cos²Ф
- sin²Ф + cos²Ф=1 ⇒ subtract sin²Ф from each side
∴ cos²Ф = 1 - sin²Ф
- cscФ = 1/sinФ ⇒ cscФ × sinФ = (1/sinФ) × sinФ = 1
* Now lets solve the problem sinФ × cscФ - sin²Ф
∵ sinФ × 1/sinФ = 1
∴ sinФ × cscФ - sin²Ф = 1 - sin²Ф
∵ 1 - sin²Ф = cos²Ф
∴ sinФ × cscФ - sin²Ф = cos²Ф
* The answer is cos²Ф
