Write the geometric sequence in function notation.
1) f(x) = (4) ⋅ (1∠•4)x – 1
2) f(x) = (4) ⋅ (1∠•2)x – 1
3) f(x) = (2) ⋅ (1∠•4)x – 1
4) f(x) = (2) ⋅ (1∠•2)x – 1