Function Returning an array in Fortran

It is my understanding that you can return an array from a function in Fortran, but for some reason my code is only returning the first value in the array I am asking it to return. This is the function:

function polynomialMult(npts,x,y)
    integer npts
    double precision x(npts), results(npts + 1), y(npts,npts)

    polynomialMult =  x(1:npts) + 1

end function

and this is where I'm calling it

 C(1:numPoints) = polynomialMult(numPoints,x,f)

print *, C(1:numPoints)`

right now it doesn't do anything useful because I am trying to understand the syntax before I write the logic. I saw some stuff about specifying types for functions, but when I write

integer function polynomialMult(npts,x,y)

or whatever I get a compilation error.