Function Trouble again?

Question

im sorry but i need some more help. i got the following answers for the problem but i am lost and need help. im getting a tutor tomorow.

for 1 i got undefined and 2 i got 6.7x2-3? please help me in any way possiable, thanks so much!

1. given f9x0=1-2x2, find f(x+ triangle thing x ) -f (x) over triangle thing x, for hear i got undefined

2. f (x) = 3x+1 g(x) = x2 -3, and for hear i got 6.7x2-3. oh my god anyone please guide me or tell me any good websights, is there any way to check my work or what? thanks you so much in advanced i really appricate it:}

Answer 1

Let triangle thing = h
Then f(x) = 1-2x^2
f(x+h) = 1- 2(x+h)^2)= 1-2x^2-4xh -2h^2
f(x+h) -f(x) = 1-2x^2-4xh -2h^2 -1 +2x^2 =4xh -2h^2
[f(x+h)-f(x)]/h = h(4x-2h)/h = 4x-2h
Now let h --> 0 and we get 4x as our answer.

Not sure what the question is in 2nd problem
I will assume it is to find f(g(x))
= 3(x^2-3) +1 = 3x^3-9+1= 3x^2 - 8

Answer 2

x+ triangle thing x

hehe