Question

If f={(-1,-3), (1,1),(2,3),(4,6)} and g={(-1,-1),(1,7),(4,3)} what is (f+g)(4)?

Answer 1

(f + g)(4) = 9

Explanation:

We have that:

f = {(-1,-3), (1,1),(2,3),(4,6)}

this means that:

f(-1) = -3

f(1) = 1

f(2) = 3

f(4) = 6

and we also know that:

g = {(-1,-1),(1,7),(4,3)}

hich means that:

g(-1) = -1

g(1) = 7

g(4) = 3

Now we want to find:

(f + g)(4)

For the general case of two functions f(x) and g(x)

(f + g)(x) = f(x) + g(x)

Then:

(f + g)(4) = f(4) + g(4)

and we know both of these values, so we can just replace them:

(f + g)(4) = f(4) + g(4) = 6 + 3 = 9

Then we get:

(f + g)(4) = 9