Solving for unknown variable

adilch

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Jul 30, 2013
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Hi all, I am new to this forum, can any body please help with this. I have got the following equation and how I can solve it for T, if I have all the values for other variables, I tried to do this, but it got little complicated for me, So you any one here can help me with this that would be great. Thanks
P = 100 * 1.334 * (10.0)^(A - (B / (T + C))
 
P = 100 * 1.334 * (10.0)^(A - (B / (T + C)) =>

P/(100*1.334)=
(10.0)^(A - (B / (T + C)) =>

P/133.4=
(10.0)^(A - (B / (T + C)) =>

log(10)(P/133.4)=
A - B / (T + C) =>

B / (T + C) =A-log(10) (P/133.4) =>

B/(
A-log(10) (P/133.4))=T+C =>

T=
B/(A-log(10) (P/133.4))-C
 
Last edited by a moderator:
Bracket missing; I'll assume you mean this:
P = 100 * 1.334 * (10.0)^(A - (B / (T + C)))

Let D = 100 * 1.334 ; then:
D * 10^(A - B / (T + C)) = P
10^(A - B / (T + C)) = P / D

Let E = P / D ; then:
10^(A - B / (T + C)) = E
A - B / (T + C) = Log(E) / Log(10)

Let F = Log(E) / Log(10) ; then:
A - B / (T + C) = F
(A(T + C) - B) / (T + C) = F
AT + AC - B = F(T + C)
AT + AC - B = FT + FC
FT - AT = AC - B - FC
So:
T = (AC - B - FC) / (F - A)
or:
T = (C(A - F) - B) / (F - A)

Mathmari: one of us is wrong! Who wants to be referee? :rolleyes:

Denis, that is an incorrect conclusion. You brought in variables D, E, and F. Your solution looks different.


The following test is not conclusive, but it is promising:


Let A = 3.

Let B = 10.

Let C = 3.

Let P = 1,334.

Let T = 2.


When the values are substituted in mathmari's final equation and in Denis's set of equations,

then each side of the equations equal each other, respectively.
 
Bracket missing; I'll assume you mean this:
P = 100 * 1.334 * (10.0)^(A - (B / (T + C)))

Let D = 100 * 1.334 ; then:
D * 10^(A - B / (T + C)) = P
10^(A - B / (T + C)) = P / D

Let E = P / D ; then:
10^(A - B / (T + C)) = E
A - B / (T + C) = Log(E) / Log(10)

Let F = Log(E) / Log(10) ; then:
A - B / (T + C) = F
(A(T + C) - B) / (T + C) = F
AT + AC - B = F(T + C)
AT + AC - B = FT + FC
FT - AT = AC - B - FC
So:
T = (AC - B - FC) / (F - A)
or:
T = (C(A - F) - B) / (F - A)

Mathmari: one of us is wrong! Who wants to be referee? :rolleyes:

I think we have similar results, the only difference is that at the logarithm I used the base 10 so log(10)10=1 and you used an other base...
 
Thanks

Thanks a lot guys for this great help :) I am not in touch with these exponential equations for quite long. thanks once again :)
 
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