Skip to main content
Ch. 5 - Integration
5์žฅ, ๋ฌธ์ œ 5.RE.15a

Symmetry properties Suppose โˆซโ‚€โด ฦ’(๐“) d๐“ = 10 and โˆซโ‚€โด g(๐“) d๐“ = 20. Furthermore, suppose ฦ’ is an even function and g is an odd function. Evaluate the following integrals.


(a) โˆซโ‚‹โ‚„โด ฦ’(๐“) d๐“

๊ฒ€์ฆ๋œ ๋‹จ๊ณ„๋ณ„ ์•ˆ๋‚ด
1
Step 1: Understand the symmetry properties of even and odd functions. An even function satisfies ฦ’(๐“) = ฦ’(-๐“), meaning it is symmetric about the y-axis. An odd function satisfies g(๐“) = -g(-๐“), meaning it is symmetric about the origin.
Step 2: Recall the property of definite integrals for even functions. If ฦ’(๐“) is even, then โˆซโ‚‹โ‚โ‚ ฦ’(๐“) d๐“ = 2โˆซโ‚€โ‚ ฦ’(๐“) d๐“. This property will be used to evaluate โˆซโ‚‹โ‚„โด ฦ’(๐“) d๐“.
Step 3: Substitute the given value of โˆซโ‚€โด ฦ’(๐“) d๐“ = 10 into the formula for even functions. Using the property, โˆซโ‚‹โ‚„โด ฦ’(๐“) d๐“ = 2โˆซโ‚€โด ฦ’(๐“) d๐“.
Step 4: Simplify the expression by multiplying the given value of โˆซโ‚€โด ฦ’(๐“) d๐“ by 2. This will give the result for โˆซโ‚‹โ‚„โด ฦ’(๐“) d๐“.
Step 5: Conclude that the integral โˆซโ‚‹โ‚„โด ฦ’(๐“) d๐“ depends entirely on the symmetry property of the even function and the given value of โˆซโ‚€โด ฦ’(๐“) d๐“.

๋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:
1m

์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.

Even Functions

An even function is defined by the property that ฦ’(โˆ’x) = ฦ’(x) for all x in its domain. This symmetry about the y-axis implies that the area under the curve from -a to 0 is equal to the area from 0 to a. Therefore, when integrating an even function over a symmetric interval, the integral can be simplified to twice the integral from 0 to a.
์ถ”์ฒœ ์˜์ƒ:
6:13
Exponential Functions

Odd Functions

An odd function satisfies the condition g(โˆ’x) = โˆ’g(x) for all x in its domain. This property indicates that the function is symmetric about the origin, leading to the conclusion that the integral of an odd function over a symmetric interval around zero is zero. Thus, when evaluating the integral of an odd function from -a to a, the contributions from the negative and positive sides cancel each other out.
์ถ”์ฒœ ์˜์ƒ:

Definite Integrals and Symmetry

Definite integrals represent the net area under a curve between two points. When evaluating integrals of even and odd functions over symmetric intervals, the properties of these functions allow for simplifications. For even functions, the integral from -a to a can be expressed as twice the integral from 0 to a, while for odd functions, the integral from -a to a equals zero, highlighting the importance of symmetry in calculus.
์ถ”์ฒœ ์˜์ƒ:
๊ฐ€์ด๋“œ ์ฝ”์Šค
05:43
Definition of the Definite Integral
๊ด€๋ จ ์‹ค์ฒœ
๊ต๊ณผ์„œ ์งˆ๋ฌธ

Explain why or why not Determine whether the following statements are true and give an explanation or counterexample.

(a) If ฦ’ is symmetric about the line ๐“ = 2 , then โˆซโ‚€โด ฦ’(๐“) d๐“ = 2 โˆซโ‚€ยฒ ฦ’(๐“) d๐“.

64
views
๊ต๊ณผ์„œ ์งˆ๋ฌธ

Function defined by an integral Let ฦ’(๐“) = โˆซโ‚€หฃ (t โ€• 1)ยนโต (tโ€•2)โน dt .

(c) For what values of ๐“ does ฦ’ have local minima? Local maxima?

57
views
๊ต๊ณผ์„œ ์งˆ๋ฌธ

Geometry of integrals Without evaluating the integrals, explain why the following statement is true for positive integers n:

โˆซโ‚€ยน ๐“โฟd๐“ + โˆซโ‚€ยน โฟโˆš(๐“d๐“) = 1

70
views
๊ต๊ณผ์„œ ์งˆ๋ฌธ

Area of regions Compute the area of the region bounded by the graph of ฦ’ and the ๐“-axis on the given interval. You may find it useful to sketch the region.                                              

                                                                                                                                                                                    

 ฦ’(๐“) = 2 sin ๐“/4 on [0, 2ฯ€]

103
views
๊ต๊ณผ์„œ ์งˆ๋ฌธ

Symmetry properties Suppose โˆซโ‚€โด ฦ’(๐“) d๐“ = 10 and โˆซโ‚€โด g(๐“) d๐“ = 20. Furthermore, suppose ฦ’ is an even function and g is an odd function. Evaluate the following integrals.


(e) โˆซโ‚‹โ‚‚ยฒ 3๐“ฦ’(๐“)d๐“

57
views
๊ต๊ณผ์„œ ์งˆ๋ฌธ

Symmetry properties Suppose โˆซโ‚€โด ฦ’(๐“) d๐“ = 10 and โˆซโ‚€โด g(๐“) d๐“ = 20. Furthermore, suppose ฦ’ is an even function and g is an odd function. Evaluate the following integrals.


(c) โˆซโ‚‹โ‚„โด (4ฦ’(๐“) โ€• 3g(๐“))d๐“

64
views