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Ch. 2 - Graphs and Functions
Lial - College Algebra 13th Edition
Lial13th EditionCollege AlgebraISBN: 9780136881063당신이 사용하는 게 아니라요?교과서 변경
3장, 문제 25

Determine whether each equation defines y as a function of x. y = 6 -x2

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1
Recall the definition of a function: for each input value of x, there must be exactly one output value of y.
Look at the given equation: \(y = 6 - x^{2}\).
For any value of x, calculate the right side \(6 - x^{2}\) to find the corresponding y value.
Since squaring x (\(x^{2}\)) always gives a non-negative result and subtracting it from 6 gives a unique y for each x, there is only one y for each x.
Therefore, the equation defines y as a function of x because each x corresponds to exactly one y.

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이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
영상 길이:
55s
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주요 개념

질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.

Definition of a Function

A function is a relation where each input (x-value) corresponds to exactly one output (y-value). This means for every x, there is only one y. Understanding this helps determine if an equation defines y as a function of x.
추천 영상:
5:57
Graphs of Common Functions

Evaluating Equations for Function Criteria

To check if an equation defines y as a function of x, substitute values of x and see if y has a unique value. If each x produces only one y, the equation represents a function.
추천 영상:
4:26
Evaluating Composed Functions

Quadratic Functions and Their Graphs

The equation y = 6 - x² is a quadratic function, which graphs as a parabola opening downward. Since for each x there is only one y, quadratic equations like this define y as a function of x.
추천 영상:
5:26
Graphs of Logarithmic Functions