Can These Two Complex Math Equations Be Solved Correctly?

  • Thread starter Thread starter RaYaMe
  • Start date Start date
AI Thread Summary
The discussion revolves around solving two complex math equations in preparation for an upcoming exam. The first equation involves finding constants a and b in the relationship q=ap^b using given logarithmic values. The user attempts to derive values for a and b by taking the natural logarithm of both sides and manipulating the equations, ultimately calculating b as -0.25 and a as e^2.06. The second equation requires combining logarithms, which the user approaches by expressing logb(x) + n as a single logarithm. The responses confirm the user's methods and calculations as correct.
RaYaMe
Messages
3
Reaction score
0


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:
Mathematics news on Phys.org
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:
 
Thread 'Video on imaginary numbers and some queries'
Hi, I was watching the following video. I found some points confusing. Could you please help me to understand the gaps? Thanks, in advance! Question 1: Around 4:22, the video says the following. So for those mathematicians, negative numbers didn't exist. You could subtract, that is find the difference between two positive quantities, but you couldn't have a negative answer or negative coefficients. Mathematicians were so averse to negative numbers that there was no single quadratic...
Insights auto threads is broken atm, so I'm manually creating these for new Insight articles. In Dirac’s Principles of Quantum Mechanics published in 1930 he introduced a “convenient notation” he referred to as a “delta function” which he treated as a continuum analog to the discrete Kronecker delta. The Kronecker delta is simply the indexed components of the identity operator in matrix algebra Source: https://www.physicsforums.com/insights/what-exactly-is-diracs-delta-function/ by...
Thread 'Unit Circle Double Angle Derivations'
Here I made a terrible mistake of assuming this to be an equilateral triangle and set 2sinx=1 => x=pi/6. Although this did derive the double angle formulas it also led into a terrible mess trying to find all the combinations of sides. I must have been tired and just assumed 6x=180 and 2sinx=1. By that time, I was so mindset that I nearly scolded a person for even saying 90-x. I wonder if this is a case of biased observation that seeks to dis credit me like Jesus of Nazareth since in reality...
Back
Top