What math topics do i need to learn in order to script cframe interpolation?

I've played around with CFrame interpolation for a while, and this is a simple example of using a cos interp between two positions;

for i = 1, t do
    wait()  
    local f = i/t *pi
    local g = (1-math.cos(f)) * 0.5
    Part.CFrame = CFrame.new(X1, Y1, Z1)  
    *CFrame.new(g*(X2-X1), g*(Y2-Y1), g*(Z2-Z1))
end

X1, Y2, Z2 mark the initial location, while X2, Y2, Z2 mark the position you're aiming for. If you need help understanding how the math works, feel free to ask.