Find the Center and Radius of the Sphere $x ^ { 2 } + y ^ { 2 } + z ^ { 2 } + 8 y + 2 z = 19$

question 59

Essay

Find the center and radius of the sphere. $x ^ { 2 } + y ^ { 2 } + z ^ { 2 } + 8 y + 2 z = 19$

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Definitions:

Categorical Variable

A variable with categorical data.

Dummy Variables

Variables used in regression analysis to represent categorical data by converting it into a series of binary values.

Levels

The different values or categories that a factor can have in an experiment or statistical model.

Multiple Coefficient

A term that does not have a standard definition in statistics or mathematics and may be confused with terms like "multiple correlation coefficient" or "multiple coefficients in regression analysis". NO.