Answer:
Ф = 0 and Ф = π
Step-by-step explanation:
* Lets explain how to solve the problem
∵ sin Ф + 1 = cos²Ф, where 0 ≤ Ф < 2π
- To solve we must to replace cos²Ф by 1 - sin²Ф
∵ sin²Ф + cos²Ф = 1
- By subtracting sin²Ф from both sides
∴ cos²Ф = 1 - sin²Ф
- Lets replace cos²Ф in the equation above
∴ sin Ф + 1 = 1 - sin²Ф
- Subtract 1 from both sides
∴ sin Ф = - sin²Ф
- Add sin²Ф for both sides
∴ sin²Ф + sin Ф = 0
- Take sin Ф as a common factor from both sides
∴ sin Ф(sin Ф + 1) = 0
- Equate each factor by 0
∵ sin Ф = 0
∴ Ф = 0 OR Ф = 2π
∵ sin Ф + 1 = 0
- Subtract 1 from both sides
∴ sin Ф = -1
∴ Ф = π
∵ 0 ≤ Ф < 2π
∵ Ф < 2π
∴ We will refused the answer Ф = 2π
∴ Ф = 0 and Ф = π
