Question

If f(x)=4x2=1 and g(x)=x2-5, find (f-g)(x)A:3x2+6B:5x2-6C:3x2-4D:5x2-4

Answer 1

For this case we have the following functions:

$f (x) = 4x ^ 2 + 1\\g (x) = x ^ 2-5$

We must find$(f-g) (x):$

By definition of operations with functions we have:

$(f-g) (x) = f (x) -g (x)$

So:

$(f-g) (x) = f (x) -g (x) = 4x ^ 2 + 1- (x ^ 2-5) = 4x ^ 2 + 1-x ^ 2 + 5 = 3x ^ 2 + 6$

Answer:

Option A

$3x ^ 2 + 6$