How Many Critical Points Does the Following Function Have $f ( x , y ) = 4 - \left( y ^ { 2 } + x ^ { 2 } \right)$

question 90

Multiple Choice

How many critical points does the following function have $f ( x , y ) = 4 - \left( y ^ { 2 } + x ^ { 2 } \right)$

• A)four
• B) one
• C) two
• D) three
• E) none

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Definitions:

Cross-Sectional Study

A research method that analyzes data from a population, or a representative subset, at a specific point in time.

Longitudinal Study

A research method that involves repeatedly observing the same subjects over a period, often years or decades, to track changes.

Demand Characteristics

Features of an experimental setting that lead participants to guess the purpose of the study, potentially influencing the behavior being studied.

Correlational Studies

Research methods that examine the relationship or correlation between two or more variables, without determining causal direction.