In Figure, the ratio of ¯¯¯¯¯¯¯¯¯DE to ¯¯¯¯¯¯¯¯EF is 4 to 9. If ¯¯¯¯¯¯¯¯¯DF=2, calculate the distance from D to the midpoint of ¯¯¯¯¯¯¯¯EF.
Prove that:(i) 13+√7+1√7+√5+1√5+√3+1√3+1=1(ii) 11+√2+1√2+√3+1√3+√4+1√4+√5+1√5+√6+1√6+√7+1√7+√8+1√8+√9=2