Question

If `f(x) = x^2 + 3x` and `g(x) = 4x - 1`, what is `(f@g)(0)`?

Answer 1

`(f@g)(0)=-2`

Explanation:

`"substitute "g(x)=4x-1" into "f(x)`

`rArrf(4x-1)`

`=(4x-1)^2+3(4x-1)`

`=16x^2-8x+1+12x-3`

`=16x^2+4x-2`

`rArr(f@g)(x)=16x^2+4x-2`

`"to evaluate "(f@g)(0)" substitute x = 0 into "(f@g)(x)`

`rArr(f@g)(0)=0+0-2=-2`