Question

If f(x)=2x^2+1 what is f(x) when x =3

Answer 1

The answer is:

f(3) = 19

Work/explanation:

To evaluate, plug in 3 for x.

`\sf{f(x)=2x^2+1}`

`\sf{f(3)=2(3)^2+1}`

Square 3 first.

`\sf{f(3)=2\cdot9+1}`

`\sf{f(3)=18+1}`

Add

`\sf{f(3)=19}`

Answer 2

f(x)=2x^2+1 Replace every instance of x with 3:

f(3)=2(3)^2+1 = 18+1 = 19 (answer)