Expression 10: "y" equals "a" Subscript, 0 , Baseline plus Start sum from "n" equals 1 to "k" , end sum, left parenthesis, "A" left bracket, "n" , right bracket sin left parenthesis, "n" pi "x" , right parenthesis plus "B" left bracket, "n" , right bracket sin left parenthesis, "n" pi "x" , right parenthesis , right parenthesisy=a0+k∑n=1Ansinnπx+Bnsinnπx