Question

Make "v" the subject of the formula:

m = m / (sqrt 1 - (v/c)^2 )

Lol kinda eh confusing...just hmu n I'll clarify anything.

Answer 1

from looking at it v should equal 0 but lets go thru it

divide each side by m:
1=1/(sqrt(1-(v/c)^2))
multiply each side by the denominator on the right:
sqrt(1-(v/c)^2)=1
square both sides
1-(v/c)^2=1
subtract a 1 from each side
-(v/c)^2=0
multiply each side by (-1)
(v/c)^2=0
square root both sides
v/c=0

this can only occur if
v=0 and \[c \neq0\]

Answer 2

Makes sense Jah. Thank you. :)