Question

n+1分之1乘n+2分之1为什么等于n+1分之1减n+2分之1求公式推导

Answer 1

1/(n+1) * 1/(n+2)

=(n+2-n-1) / (n+1)(n+2)

=(n+2)/(n+1)(n+2) - (n+1)/(n+1)(n+2)

=1/(n+1) - 1/(n+2)