Can These Two Complex Math Equations Be Solved Correctly?

  • Context: Undergrad 
  • Thread starter Thread starter RaYaMe
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Discussion Overview

The discussion revolves around solving two complex mathematical equations involving logarithmic relationships and constants. The scope includes mathematical reasoning and problem-solving in preparation for an exam.

Discussion Character

  • Homework-related
  • Mathematical reasoning

Main Points Raised

  • One participant presents two equations: the first relates variables p and q through the equation q=ap^b, and the second involves combining logarithmic expressions.
  • Another participant suggests showing their work to facilitate assistance and engages with the first equation by taking the natural logarithm of both sides.
  • A participant attempts to derive values for a and b from the first equation, leading to a calculation for b as -0.25 and subsequently for a as e^2.06.
  • There is a proposed method for the second equation that involves rewriting logb(x) + n as a single logarithm, with some uncertainty expressed about the cancellation of terms.

Areas of Agreement / Disagreement

Participants express varying degrees of confidence in their approaches, with one participant affirming the correctness of another's method. However, there is no consensus on the final values of a and b, nor is there agreement on the handling of the logarithmic expression.

Contextual Notes

Participants do not clarify assumptions or dependencies in their calculations, and there are unresolved steps in the mathematical reasoning presented.

Who May Find This Useful

Students preparing for exams in mathematics or those interested in logarithmic equations and their applications may find this discussion relevant.

RaYaMe
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Hi every body , I had a lot of equations to solve yesterday

becouse that i was preparing my self for my exam this sunday

and I've did .. but these TWO equations .. i couldn't be sure about my results

can you help me to solve them ..

1- The variables p and q are related by the law q=ap^b , where a and b are constants . Given that ln(p) = 1.32 when ln(q)= 1.73 and ln(p)=0.44 when ln(q)=1.95 ,
find the values of a and b .

2- Write logb (x) + n as one logarithm


* b is the base

 
Last edited:
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Welcome to PF!

Hi RaYaMe! Welcome to PF! :smile:

(try using the X2 tag just above the Reply box :wink:)

Show us what you got, and then we'll know how to help! :smile:
 
for the second one ..
2- Write logb (x) + n as one logarithm

i've tried =>

logb (x) + logb (b)^n = logb (X.b^n) ?? or it's canceled

:biggrin:

AND ..the first one .. i tried to take ln of both sides ( q=ap^b)

lnq = lna + b lnp

It'll be >> 1- 1.73= lna + 1.32 b

>> 2- 1.95 = lna + 0.44 b

that's what I've did to get the value of " b "

1.73=lna + 1.32 b
-1.95 = -lna - 0.44 b
___________________
-0.22 = 0.88 b >>>>> b= -0.22/0.88 = -0.25

1.73 = lna + ( 1.32 * -0.25 )
1.73 + 0.33 = lna
2.06 = lna

so , a = e^2.06 :biggrin: what do you think about my ways ..
 
Last edited:
RaYaMe said:
logb (x) + logb (b)^n = logb (X.b^n)

-0.22 = 0.88 b >>>>> b= -0.22/0.88 = -0.25

1.73 = lna + ( 1.32 * -0.25 )
1.73 + 0.33 = lna
2.06 = lna

so , a = e^2.06 :biggrin: what do you think about my ways ..

Yes, that looks fine! :smile:
 

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