Answer:
Sₙ = √5/2 n (n + 1)
Step-by-step explanation:
<u>Given AP:</u>
<u>Rewriting as:</u>
- √5,√4*5,√9*5,√16*5,...
- √5, 2√5, 3√5, 4√5,..., n√5
<u>Common difference:</u>
<u>Sum of n terms:</u>
- Sₙ = 1/2n (a₁ + aₙ) =
- 1/2n (√5 + √5 + (n-1)√5) =
- 1/2n (n + 1)√5=
- √5/2 n (n + 1)
Sₙ = √5/2 n (n + 1)
Answer:
Bob could predict a <u>100%</u>, as if he has studied for a long time, and has learnt the content, he should be able to get 100%!
Note that
a² - b² = (a+b)(a-b)
i² = -1 by definition.
We want to factorize x² + 36 = x² + 6².
Consider the expression
x² - (6i)² = x² - (6²)(i²) = x² - 36i² = x² + 36
Because x² - (6i)² = (x + 6i)(x - 6i)
Therefore
x² + 36 = (x + 6i)(x - 6i)
Answer: (x + 6i)(x - 6i)
