The derivation method of this sequence is The sum formula of the first n terms of the arithmetic sequence {an} is_____ The derivation method is as follows_______ The general formula of equal ratio sequence {an} is_____ The derivation method is as follows_______ The sum formula of the first n terms of the equal ratio sequence {an} is_______ The derivation method is as follows________ I just want to know what the derivation method is, so you just fill in the derivation method

The derivation method of this sequence is The sum formula of the first n terms of the arithmetic sequence {an} is_____ The derivation method is as follows_______ The general formula of equal ratio sequence {an} is_____ The derivation method is as follows_______ The sum formula of the first n terms of the equal ratio sequence {an} is_______ The derivation method is as follows________ I just want to know what the derivation method is, so you just fill in the derivation method

An = a1 + (n-1) d, inductive method
An = A1 * q ^ (n-1), induction
Sn = a 1 (1-Q ^ n) / (1-Q), dislocation subtraction