Here it is:

in the theory of relativity, the mass,mof a particle with velocityvis given by:

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

wherecis the speed of light, andmois the mass of the particle at rest. What happens to the mass of the particle as its velocity approaches the speed of light?

we've been doing limit laws recently, so I assume im ment to use those, but this really is nothing like anything I'v seen before and im completely stuck.