Question

f(x)=2x²+1 what is f(x) when x=3?

Answer 1

f(x)=2x^2+1
f(3)=2(3)^2+1
f(3)=2(9)+1
f(3)=18+1
f(3)=19

Answer 2

$f(x) = 2x^2 +1 \\\\f(3) = 2(3)^2 + 1\\\\f(3) = 2(9) + 1\\\\f(3) = 18 + 1\\\\\boxed{\bf{f(3)=19}}$