Cot^2x - cot^2x cos^2x
= cot^2x - {(cot^2x)(cos^2x)}
= cot^2x { 1 - cos^2x }
= cot^2x { sin^2x }
= (cos^2x/sin^2x) { sin^2x }
= cos^2x

As

, the sequence

converges to zero.
If you're talking about the infinite series

well we've shown by comparison that this series must also converge because we know any geometric series

will converge as long as

.
Answer:
1A, 2C, 3X, 4A, 5B, 6W, 7X
Step-by-step explanation:
Im not sure about these answers, can you have the same letter for a different number?
U basically solve: (4sqrt8)*2 + (5 sqrt 12 + 6 sqrt 20)*2