Question

If f(x)=4-x^and g(x)=6x,which expression is equivalent to (g-f)(3)

Answer 1

f(x)=4-x^2 and g(x)=6x

find (g -f)(3)

We know (g - f)(x) = g(x) - f(x)

(g -f)(3) = g(3) - f(3)

LEts find g(3)

we know g(x) = 6x . so g(3) = 6(3) = 18

We know
`f(x) = 4-x^2 \ so \ f(3) = 4-(3)^2 = 4- 9 = -5`

(g -f)(3) = g(3) - f(3) , we got g(3) = 18 and f(3) = -5

(g -f)(3) = 18 - (-5) = 18 + 5 = 23

(g-f)(3) = 23

Expression is (g-f)(3) = g(3) - f(3) =
`6(3) - (4-(3)^2))`