Sequences and Series Equations

• The sum to n terms of an arithmetic series is given by the formula Sn = n/2[2a + (n-1)d]
• What is the formula for nth term of an arthemetic series?

  $Un=$$a+$$d(n-1)$
• What is the equation for arthemtic series?

  $Sn=$$\ n/2 ( 2a+d(n-1))$