Question

Let f(x)=3x^2+3x+4

what is
f(−a)=

f(a+1)=

2f(a)=

f(2a)

Answer 1

\[\Large f(x)=3x^2+3x+4\]


\[\Large f(-a)=3(-a)^2+3(-a)+4\]


\[\Large f(-a)=3a^2-3a+4\]

Answer 2

\[\Large f(x)=3x^2+3x+4\]


\[\Large f(a+1)=3(a+1)^2+3(a+1)+4\]


\[\Large f(a+1)=3(a^2+2a+1)+3(a+1)+4\]


\[\Large f(a+1)=3a^2+6a+3+3a+3+4\]


\[\Large f(a+1)=3a^2+9a+10\]

Answer 3

I'll let you try the other two