Answer
(a) $f(3)=26$
(b) $f(-4)=19$
Work Step by Step
RECALL:
$f(a)$ represents the value of the function $f$ when $x=a$.
Replace $x$ with the given value to obtain:
(a)
$f(3) = 2(3^2)+3(3)-1
\\f(3)= 2(9)+9-1
\\f(3)=18+9-1
\\f(3)=26$
(b)
$f(-4) = 2(-4)^2+3(-4)-1
\\f(-4)=2(16)+(-12)-1
\\f(-4)=32-12-1
\\f(-4)=20-1
\\f(-4)=19$
