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# 中二數學問題..快進來解答解答!THX

1. the reading of a thermometer is 37.5度 with a percentage error of 2/2/3%.

(a) find the max. absolute error.

(b) (i) find the upper and lower limits of the actual reading.

(ii) Hence,is it possible that the actual reading is 38.8度?Explain your answer.

30. A picture frame is in the shape of a rectangle.All the measurements are shown in the figure and are correct to the nearest cm.Find the max. and min. areas of the picture frame.

picture frame: 86cm x 58 cm

picture: 70cm x 42 cm

### 2 Answers

- 8 years agoFavorite Answer
we cannot do no.30 because you have no figure

no.1 I am thinking....

2011-10-05 05:13:26 補充：

1(a)Let the max absolute error be x

x/37.5X100%=2/2/3%

x=1

the max absolute error is 1

1(b)(i)The upper limits=38.5

The lower limits=36.5

1(b)(ii)no

(something like that......I am not sure....If it is wrong sorry)

2011-10-06 00:35:20 補充：

30.Thanks...

The max absolute error

=1X1/2

=0.5

The upper limit numbers

=86.5cmX58.5cm

=70.5cmX42.5cm

The max area of picture frame

=86.5X58.5-70.5X42.5cm^2

=2064cm^2

The lower limit

=85.5cmX57.5cm

=69.5cmX41.5cm

The min area of picture frame

=85.5X57.5-70.5X41.5cm^2

=1990.5cm^2

p.s我係英國

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- 8 years ago
(a) Let x be the maximum error

x/37.5 x 100% = 2/2/3%

x/37.5 = 8/300

x = 8/300 x 37.5

x = 1

So, absolute error = 1

(bi) the upper limit

=37.5℃+1

=38.5℃

the lower limit

=37.5℃-1

=36.5℃

(bii) the range of the possible actual value (say x cm) is

36.5℃ ≦ x℃＜38.5℃

∴the actual reading can not be 38.8℃

30) 什麼資料也沒有！！

P.S. 一定對！：

Source(s): me- Login to reply the answers