Answer:
-40 I wanna say
Step-by-step explanation:
If it's a geometric sequence then:

We calculate the fourth and fifth term of the sequence:

Answer:
In year 4 15.1875 animals.
In year 5 11.390625 animals.
Measure of angle 8 is 135°
(cos Ф -cos Ф)² + (cos Ф + cos Ф)²
Firstly: (cos Ф -cos Ф)² = 0² = 0
Secondly :(cos Ф + cos Ф)² = (2cos Ф)². = 4. (cos Ф)² = 4cos² Ф
Mind you when you raise a cosine (or sin or tan...) to the n power, the n power should affect the cosine only and NOT the angle Ф