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Ch. 1 - Functions
1์žฅ, ๋ฌธ์ œ 1.23

In Exercises 19โ€“32, find the (a) domain and (b) range.


๐”‚ = 2eโปหฃ - 3

๊ฒ€์ฆ๋œ ๋‹จ๊ณ„๋ณ„ ์•ˆ๋‚ด
1
Step 1: Understand the function given, which is ๐”‚ = 2eโปหฃ - 3. This is an exponential function where the base is e (Euler's number) and the exponent is -x.
Step 2: Determine the domain of the function. The domain of an exponential function is all real numbers because you can substitute any real number for x without restriction. Therefore, the domain is (-โˆž, โˆž).
Step 3: Analyze the behavior of the function to find the range. As x approaches positive infinity, eโปหฃ approaches 0, making ๐”‚ approach -3. As x approaches negative infinity, eโปหฃ becomes very large, making ๐”‚ approach positive infinity.
Step 4: Conclude the range based on the behavior of the function. Since ๐”‚ approaches -3 but never actually reaches it, and can increase without bound, the range is (-3, โˆž).
Step 5: Summarize the findings: The domain of the function is all real numbers (-โˆž, โˆž), and the range is all real numbers greater than -3, which is (-3, โˆž).

๋น„์Šทํ•œ ๋ฌธ์ œ์— ๋Œ€ํ•œ ๊ฒ€์ฆ๋œ ์˜์ƒ ๋‹ต๋ณ€:

์ด ์˜์ƒ ํ•ด๋ฒ•์€ ์œ„ ๋ฌธ์ œ์— ๋„์›€์ด ๋œ๋‹ค๊ณ  ํŠœํ„ฐ๋“ค์ด ์ถ”์ฒœํ•œ ๊ฒƒ์ž…๋‹ˆ๋‹ค.
์˜์ƒ ๊ธธ์ด:
3m
๋„์›€์ด ๋˜์—ˆ๋‚˜์š”?

์ฃผ์š” ๊ฐœ๋…

์งˆ๋ฌธ์— ์˜ฌ๋ฐ”๋ฅด๊ฒŒ ๋‹ตํ•˜๊ธฐ ์œ„ํ•ด ๋ฐ˜๋“œ์‹œ ์ดํ•ดํ•ด์•ผ ํ•˜๋Š” ํ•ต์‹ฌ ๊ฐœ๋…๋“ค์€ ๋‹ค์Œ๊ณผ ๊ฐ™์Šต๋‹ˆ๋‹ค.

Domain of a Function

The domain of a function refers to the set of all possible input values (x-values) for which the function is defined. For the function y = 2eโปหฃ - 3, the exponential function eโปหฃ is defined for all real numbers, meaning the domain is all real numbers, or (-โˆž, โˆž). Understanding the domain is crucial for determining where the function can be evaluated.
์ถ”์ฒœ ์˜์ƒ:
5:10
Finding the Domain and Range of a Graph

Range of a Function

The range of a function is the set of all possible output values (y-values) that the function can produce. For the function y = 2eโปหฃ - 3, as x approaches infinity, eโปหฃ approaches 0, making y approach -3. As x approaches negative infinity, y approaches positive infinity. Thus, the range is (-3, โˆž). Knowing the range helps in understanding the behavior of the function.
์ถ”์ฒœ ์˜์ƒ:
5:10
Finding the Domain and Range of a Graph

Exponential Functions

Exponential functions are mathematical functions of the form f(x) = a * bหฃ, where a is a constant, b is a positive real number, and x is the exponent. In the given function y = 2eโปหฃ - 3, the base e (approximately 2.718) is a natural constant, and the function exhibits rapid growth or decay. Understanding the properties of exponential functions is essential for analyzing their behavior and transformations.
์ถ”์ฒœ ์˜์ƒ:
6:13
Exponential Functions