The Radius of a Right Circular Cylinder Is Increasing at a Rate

question 79

Multiple Choice

The radius of a right circular cylinder is increasing at a rate of 9 inches per minute, and the height is decreasing at a rate of 7 inches per minute. What is the rate of change of the surface Area when the radius is 12 inches and the height is 32 inches?

• A) \(936 \pi \mathrm { in. } ^ { 2 } / \mathrm { min }\)
• B) \(984 \pi\) in. \(^ { 2 } / \mathrm { min }\)
• C) \(876 \pi\) in. \(^ { 2 } / \mathrm { min }\)
• D) \(840 \pi\) in. \(^ { 2 } / \mathrm { min }\)
• E) \(968 \pi\) in. \(^ { 2 } / \mathrm { min }\)

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Definitions:

Operating Income

Earnings before interest and taxes (EBIT), representing the profit from a company’s ordinary, core business operations.

Contribution Format

An income statement layout that separates fixed and variable costs, allowing for the calculation of contribution margin and easier analysis of profitability.

Operating Income

A financial metric that shows how much of a company's revenue is left over after paying for variable costs of production like wages and raw materials.

Contribution Format

A method of income statement presentation that separates fixed costs from variable costs to show the contribution margin.