[R] applying a function over an array

[BJ]

Is there a way to apply a function with several arguements over an 
array? For instance if you had a function d<-function(a,b,c) {a+b+c} and 
a 4,3 array, could you apply the function over each line of the array? 
tapply seems to only allow one argument, and I just can't think of a way 
to explicitly tell R that I am passing it 3 distinct objects instead of 
1 complex one.  Thank you as always for your help. ~Erithid