Question

If f : R → R, given by f(x) = x² + 3, then find the pre image of 2 under f. [A] 7 [B] 5 [C] -1 [D] Does not exist.​

Answer 1

Answer:

Correct option is

C

{4,−4},φ

For pre image of 17 we have:

f(x)=x

2

+1=17

⇒x

2

+1=17

⇒x

2

=16

⇒x=

16

⇒x=±4

So, x∈{−4,4}

For pre image of −3 we have:

f(x)=x

2

+1=−3

⇒x

2

+1=−3

⇒x

2

=−4 (NOT possible)

Hennce, no possible pre image.

So, x∈ϕ

Step-by-step explanation:

i hope it was helpful