Find the perimeter. Simplify the answer.

Write a recursive sequence that represents the sequence defined by the following explicit formula:

Use the radius you found in part i (r=26.8 cm) with the surface area formula below to find the surface area of the sphere. show your work and round your answer to the nearest tenth. the surface area of a sphere: sa = 4πr^2 self note: 3.8.4

[10 points, algebra 2]according to my answer key the restrictions are -1 and 4. but why not positive 1?