Saved Bookmarks
| 1. |
Let `f(x)`be periodic and `k`be a positive real number such that `f(x+k)+f(x)=0fora l lx in Rdot`Prove that `f(x)`is periodic with period `2kdot` |
|
Answer» We have `f(x+k)+f(x)=0 AA x in R` or ` f(x+k)= -f(x) AA x in R` Put `x=x+k.` Then, or `f(x+2k)= -f(x+k) AA x in R` or ` f(x+2k) = f(x), AA x in R " "[ "As "f(x+k)= -f(x)]` which clearly shows that f(x) is periodic with period 2k. |
|