How can I write log(e) in MATLAB?

I am trying to calculate x=log(e) but I can not. Any help?

[sultana saffi]

x=log(e)

[sultana saffi]

how can i give this function

[sultana saffi]

I am trying to calculate x=log4(256) but i can not.Any help pleas?

[sultana saffi]

x=log4(256)

[John D'Errico]

@sultana saffi

https://www.purplemath.com/modules/logrules5.htm

Surely you can read the formula from that site?

[Walter Roberson]

f = @(x) 4.^x - 256;
log4_256 = fzero(f, 1.2345)

log4_256 = 4

4^log4_256

ans = 256

Answer 1

[David Fletcher]

I assume you mean log10? In Matlab log is base e, so log(e)=1

x=log10(exp(1))

[Melika Qahqaie]

Thanks alot

[Walter Roberson]

Note that very few programming languages use log() to indicate log base 10. Excel is the only one I have been able to find. log() or Log[] seems to represent natural log in nearly all languages.

As mentioned Excel uses log for base 10 by default; it has no built in natural log, requiring that a decimal approximation of e be passed as the second parameter for natural log.

I did find one language Kotlin that uses ln for natural log despite being supposedly interoperable with java which uses log for natural log...

[Melika Qahqaie]

thanks for the helpful information

[sultana saffi]

tanx

[sultana saffi]

can you help with this pleas x=log4(256)

[John D'Errico]

@sultana saffi Please stop spamming this question with answers and comments to compute a log to do your homework.

Do you know the basic rule for logs to other bases?

The formula is given here:

https://www.purplemath.com/modules/logrules5.htm