Answer:
4.
Step-by-step explanation:
9(2) = 18
18-14=4
Answer:
The answer is 5184. Hope it helps luv
<u>Answer</u> : The demonstration is below :)
Step-by-step explanation :
<u>We use Pythagoras' </u><u>theorem </u><u>:</u>
- In the triangle ABC we have :
AB² = AC² - BC² = 15² - 9² = 144 = 12²
- In the triangle ABD we have :
DB² = AD² - AB² = 13² - 12² = 5²
cos(a) = BD/AD = 5/13
It's pretty clear what the pattern is - 2^(k-1) * (-1)^(k-1) would work backwards, but we have to work forwards to get lower in this case, so we could start at -3 (as long as we put the k-1 in absolute value to make sure it's not 1/8), so we could write it as ∑ (k=1, goes to 4) 2^(|k-4|)*(-1)^(k-4)
It doesn't matter for k-4 because 1/-1 and 1/1 are the same thing as -1 and 1 respectively