A(n)=4+4(n-1)
a(n)=4+4n-4
a(n)=4n
76=4n
n=19
The sum of any arithmetic sequence (series are infinite) is:
(a+a(n))(n/2)
The average of the first and last terms times the number of terms, in this case we found that n=19 so:
19(4+76)/2=760
When you draw this out, what you have is a right triangle problem. The height of the rope from the ground is 12 (a side), the distance she is from the base of the tree is 5 (a side), and the length of the rope is the hypotenuse. Use Pythagorean's Theorem to find the length of the hypotenuse: 5^2+12^2 = c^2 or
25+144 = c^2 and c^2 = 169, which makes the length of the rope come out to be 13 feet long.
The coefficient of n is 1
3.5 yards
Step by step explanation This is how I got the answer to your question and I gave you the solution I hope this helps you out