How to use subtitution in solving equation ??

i have an equation like this

total = volume * barrel

using subs( total, {volume, barrel}, {3, 4}) i can solve for total

but if i have total and volume , how can i solve for barrel ?

[Azzi Abdelmalek]

What are total and volume?

Answer 1

[Sean de Wolski]

doc solve

[hai]

solve( total, barrel ), then we have function barrel = total / volume , then we use subs(new_function,{total, volume}, {12,4}) . Is this what you mean) ?

Answer 2

[hai]

i mean if i have the total is 12 , and the volume is 4 , then i must solve that the we have 3 barrel, how we can do that in matlab ?

[Sean de Wolski]

Personally, I would use fzero()

t = 12;
v=4;
fzero(@(b)v*b-t,pi)

[hai]

it work ,but i don't want to change the equation at all, i want to keep t = v*b .