Let `A={-2,\ -1,\ 0,\ 1,\ 2}a n d\ f: A->Z` be given y `f(x)=x^2-2x-3.` Find: i. the range of `f` ii. pre images of 6,-3 and 5.

Explanation

Let x be the pre-image of −3.Then,

`f(x)=−3⇒x^2−2x−3=−3`

`⇒x^2−2x=0`

`⇒x(x−2)=0`

`⇒x=0,2`

Clearly,0 and 2 are pre-images of −3

Let x be the pre-image of 5.Then,

`f(x)=5⇒x^2−2x−3=5`

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