Question

Let f: R R be given by f(x)= x2 +1 find the

preimage of 17
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Answer 1

$\Huge{\color{blue}{\underline{\underline{Answer:-}}}}$

For pre image of 17 we have:

$\sf f(x)=x ^2 +1=17\\ \sf⇒x^ 2 +1=17\\ \sf⇒x ^2 =16\\ \sf⇒x= \sqrt{16}\\ \sf ⇒x=±4\\ \sf So, x∈[−4,4]$