Equation for logarithmic linear equation

[ldante]

Hi

Need some help to create an equation for the 6 cases of  linear graph I attached the mathcad prime for your reference.

 I cannot make the graph straight using  this formula ( y= mx+b)  because x  should be   in  logarithmic  distance

Physical Mathematics

[LucMeekes]

Hi Lex,

It's not completely clear what you want...

What you have is y=m*log(x)+b.

If you solve m and b in:   y1=m*x1+b

you get m=-0.01974 and b=3.21776.

You can do the same for the other sets.

Does this help?
Success!
Luc

[MJG]

I think OP is looking for your equation y=m*log(x)+b.

If you solve for m & b in  y1=m*log(x1)+b

you get m=-0.52532 and b=3.17596

[ldante]

Yes .. I need an equation . I am using  logarithmic scaling in x axis  .  Thank you in advance  🙂

[MJG · Accepted solution]

ldante,

The equation is y=m*log(x)+b

For x1 & y1, this can be found to be y1=-0.52532*log(x1)+3.17596.

[ldante]

Got it thanks

[LucMeekes]

Guess you're right. Forgot to type the log().

Luc