Sarah asked in 教育及參考書教學 · 8 years ago

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.

Update:

picture frame: 86cm x 58 cm

picture: 70cm x 42 cm

2 Answers

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  • 8 years ago
    Favorite 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
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