Solve the Formula for the Indicated Letter $$A = \frac { 1 } { 3 } \pi r ^ { 2 } \text { for } r$$

question 12

Multiple Choice

Solve the formula for the indicated letter. Assume that all variables represent nonnegative numbers.
- $$A = \frac { 1 } { 3 } \pi r ^ { 2 } \text { for } r$$

• A) \(r = \frac { 3 \pi } { \mathrm { A } }\)
• B) \(r = \sqrt { \frac { \mathrm { A } } { 3 \pi } }\)
• C) \(r = 3 \sqrt { \mathrm { A } \pi }\)
• D) \(r = \sqrt { \frac { 3 \mathrm {~A} } { \pi } }\)

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Definitions:

Positive Reinforcer

A positive reinforcer is any stimulus that, when presented after a behavior, increases the likelihood of that behavior being repeated.

Secondary Reinforcer

Any reinforcer that becomes reinforcing after being paired with a primary reinforcer, such as praise, tokens, or gold stars.

Extinction

In psychology, the gradual weakening and eventual disappearance of a conditioned response when the conditioned stimulus is no longer paired with an unconditioned stimulus.

Conditioned Fear

A learned response to a stimulus that was previously neutral but has been paired with an aversive event.