Which of the following is/are true for the formula 2C/a = a/(b^2) ?
I. C is the subject of the formula.
II. When a=2 and b=1, C=1.
III. When b=4 and C=2, a=4
A. I only
B. II only
C. I and II only
D. II and III only
數學MC題
2008-03-15 11:53 pm
回答 (2)
2008-03-16 1:10 am
✔ 最佳答案
C. I and II onlyI.
2C/a=a/(b^2)
2C=[a/(b^2)]^a
2C=(a^a)/(b^2)
C=(a^a)/(b^2)/2
C=0.5(a^a)/(b^2)
II.
2(1)/2=2/(1^2)
2/2=2/2
1=1
L.H.S.=R.H.S.
III.
2(2)/4=4/(4^2)
4/4=4/8
1=1/2
L.H.S.is not equal to R.H.S.
2008-03-16 12:04 am
A, I only.
(i) II is wrong
because
LHS(Left hand side)
=2/2
=1
RHS(Right hand side)
=2/1
=2
LHS is not equal to RHS.
(ii) III is wrong
because
LHS
=4/4
=1
RHS
=4/4^2
=4/16
=1/4
LHS is not equal to RHS.
therefore the answer is A, I only.
(i) II is wrong
because
LHS(Left hand side)
=2/2
=1
RHS(Right hand side)
=2/1
=2
LHS is not equal to RHS.
(ii) III is wrong
because
LHS
=4/4
=1
RHS
=4/4^2
=4/16
=1/4
LHS is not equal to RHS.
therefore the answer is A, I only.
參考: a P.5 student
收錄日期: 2021-04-25 16:20:40
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