Prove or disprove the statement, if f(x) = f(y), then x=y

The given statement can be disproved by giving a simple counter-example

Using proof by contradiction method:

Let

Let

Let

As we can see that

This completes our proof by contradiction.

the smallest possible measurement of the width is 14 feet

step-by-step explanation:

let's assume length of parallelogram is 'l'

width of parallelogram is 'w'

the perimeter of a parallelogram must be no less than 40 feet

so, we get

we are given

length of parallelogram is 6 feet

so,

l=6

we can plug it

now, we can solve for w

subtract both sides by 12

divide both sides by 2

and we get

so,

the smallest possible measurement of the width is 14 feet