Hello, raj1985!

Is there a typo? .The statement isn't true.

Prove: .If , then: . . ??

We have: .

Square both sides: .

. . . . . . . . . . .

. . . . . . . . . . .

. . . . . .

. . . . . .

We have: . . for which the statement is true.

And: .

. . .

Then: .