Question

f(x) = sqrt( 3x + 7) , g(x) = sqrt(3x - 7 )
Find (f + g)(x)

Answer 1

Where are you getting stuck on this?

Answer 2

The whole thing hahah (:

Answer 3

Do you know what the \((f + g)(x)\) part means?

Answer 4

adding

Answer 5

Yes, but, I meant more like this:
\((f + g)(x) = [f(x)] + [g(x)]\)

\((f - g)(x) = [f(x)] - [g(x)]\)

\((f \times g)(x) = [f(x)] \times [g(x)]\)

\((f \div g)(x) = [f(x)] \div [g(x)]\) AKA: \(\left( \dfrac{f}{g}\right) (x) = \dfrac{[f(x)]}{[g(x)]}\)

\((f \circ g)(x) = f([g(x)]) \)

Answer 6

Yes I know that

Answer 7

OK. So what does it become when you write it out as addition?

Answer 8

sqrt(6x) ?

Answer 9

^ is this the answer

Answer 10

Rememebr your rules for adding roots?

Answer 11

The parts under the radical must match or they cannot be added.

Answer 12

okay

Answer 13

And that makes it?

Answer 14

sqrt(6x) ?

Answer 15

It is not \(\sqrt{6x}\) because \(( 3x + 7) \ne (3x - 7)\) they can not be added into one thing under a radical.

Answer 16

Ohh okay

Answer 17

do I just leave it ?

Answer 18

Yah... they snuck in a simple one. =)

Answer 19

\(\sqrt{3x + 7} + \sqrt{3x - 7 }\)

Answer 20

If it was times between them, it would be a whole different thing! But for \(\pm\) it just sits there because they do not match.

Answer 21

Aww thanks (:

Answer 22

np. Have fun!