Question

if f(x)={(3,5),(2,4),(1,7)} and g(x)=square root(x-3) what do i do to determine (f+g)(1)

Answer 1

well first, (f+g)(1) = f(1)+g(1), so the name of the game is to figure out what f(1) and g(1) is and add them

Answer 2

but i dont understand how to find f(x) if theres nothing to solve for its only sets of numbers

Answer 3

those points are solutions. For example if i have a function h(x), and i say:
h(x) = {(1,2), (3,14), (5, 8)}
What im really saying is:
h(1) = 2, h(3) = 14, h(5) = 8

Answer 4

so in this case f(1) is seven
and for the other one the g(1) i just get -2

Answer 5

you are correct on f(1), that is seven :)
for g(1), you have:
\[g(x) = \sqrt{x-3}\]
in your problem above, was it supposed to be just x - 3 without the square root?

Answer 6

no its including the square root ...can it be a negative 2 inside the square root

Answer 7

if its negative inside the square root, you are gonna need imaginary (complex) numbers.
\[g(1) = \sqrt{1-3} \Rightarrow g(1) = \sqrt{-2} \Rightarrow g(1) = i\sqrt{2}\]