Answer:
The rule of the arithmetic sequence is 13 - 2n
The 30th term is -47
Step-by-step explanation:
∵ f(n) = 11 and g(n) = -2(n - 1) = -2n + 2
∴ f(n) + g(n) = 11 + -2n + 2 = 13 - 2n
Use n = 1 , 2 , 3 , 4 to check the type of the sequence
∵ n = 1 ⇒ 13 - 2(1) = 11
∵ n = 2 ⇒ 13 - 2(2) = 13 - 4 = 9
∵ n = 3 ⇒ 13 - 2(3) = 13 - 6 = 7
∵ n = 4 ⇒ 13 - 2(4) = 13 - 8 = 5
∵ 11 , 9 , 7 , 5 is an arithmetic sequence with difference -2
∴ The rule of the arithmetic sequence is 13 - 2n
∴ The 30th term = 13 - 2(30) = -47
Answer: 50 cents
Step-by-step explanation:
Company charges 8 cents per call and the call in question is 3 minutes. Cost is;
= 3 * 8
= 24 cents
Company however stipulates that a call is 8 cents per minute or a 50-cent minimum charge per completed call, whichever is greater.
<em>50 cents is greater than the per minute total charge of 24 cents so the cost will be 50 cents.</em>
Consider the function

, which has derivative

.
The linear approximation of

for some value

within a neighborhood of

is given by

Let

. Then

can be estimated to be

![\sqrt[3]{63.97}\approx4-\dfrac{0.03}{48}=3.999375](https://tex.z-dn.net/?f=%5Csqrt%5B3%5D%7B63.97%7D%5Capprox4-%5Cdfrac%7B0.03%7D%7B48%7D%3D3.999375)
Since

for

, it follows that

must be strictly increasing over that part of its domain, which means the linear approximation lies strictly above the function

. This means the estimated value is an overestimation.
Indeed, the actual value is closer to the number 3.999374902...