Answer:
a)
, b)
, c)
,
.
Step-by-step explanation:
The volume and the surface area of the sphere are, respectively:


a) The volume of the sphere is:


b) The surface area of the sphere is:


c) The total differentials for volume and surface area of the sphere are, respectively:






Relative errors are presented hereafter:






well the quotient means the answer to a division, so in this case:
18 ÷ 1000 = 0.018
Answer:
After 460 calls plan 1 is more economical than plan 2
Step-by-step explanation:
Plan 1: 36x + 0y
Plan 2: 13x + 0.05y
36x < 13x + 0.05y
36x - 13x < 0.05y
23x < 0.05y
23/0.05x < y
460x < y
Multiply the one by the 2 and the three by the 2. Put the decimal back in and add the negative sign