Question

Find f(2) and f(a + h) when f(x) = 3x^2 + 2x + 4

Answer 1

`f(2)=20\\f(a+h)=3a^2+6ah+3h^2+2a+2h+4`

Explanation:

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

`f(2)=3(2)^2 + 2(2) + 4\\f(2)=3(4)+ 2(2) + 4\\f(2)=12+ 4+ 4\\f(2)=20`

`f(a+h)=3(a+h)^2 + 2(a+h) + 4\\f(a+h)=3(a+h)(a+h) + 2(a+h) + 4\\f(a+h)=3a^2+3ah+3ah+3h^2+2a+2h+4\\f(a+h)=3a^2+6ah+3h^2+2a+2h+4`

Answer 2

f(2) = 20

f(a+h) = 3a²+6ah+3h²+2a+2h+4

Explanation:

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

A) Putting x =2

=> f(2) = 3(2)²+2(2)+4

=> f(2) = 12+4+4

=> f(2) = 20

B) Putting x = a+h

=> f(a+h) = 3(a+h)²+2(a+h)+4

=> f(a+h) = 3a²+6ah+3h²+2a+2h+4