AKHILESH
Last Activity: 5 Years ago
given,a2,b2and c2 are in AP
=>b2-a2=c2-b2
=>[b-a][b+a]=[c+b][c-b]
=>[b-a]/[c+b]=[c-b]/[b+a]
=>[b-a]/[b+c]=[c-b]/[a+b]
=>{ [b-a]/[b+c] } * {1/[c+a] } = { [c-b]/[a+b] } * {1/[c+a] }
=>{ [b-a] } / { [b+c][c+a] } = { [c-b] } / { [a+b][c+a] }
=>{ [b-a+c-c] } / { [b+c][c+a] } = { [c-b+a-a] } / { [a+b][c+a] }
=>{ [b+c-a-c] } / { [b+c][c+a] } = { [c+a-b-a] } / { [a+b][c+a] }
=>{ [b+c]-[a+c] } / { [b+c][c+a] } = { [c+a]-[b+a] } / { [c+a][a+b] }
=>{ [b+c] / [b+c][c+a] } – { [a+c] /[b+c][c+a] } = { [c+a] / [c+a][b+a] } – { [b+a] / [c+a][b+a] }
=>{ 1/[c+a] } – { 1/[b+c] } = { 1/[b+a] } – { 1/[c+a] }
=>2 * {1/[c+a] } = {1/[b+a] } + {1/[b+c] }
therefore ,1/[a+b] , 1/[c+a] and 1/[b+c] are in AP
=> [a+b] , [c+a] and [b+c] are in HP
=> [b+c] , [c+a] and [a+b] are in HP