Still that problem.

Well, Sorry but I couldn't find help @ Homework section, I try out here:
Ok, they tell me to find a and b so that the function:
f(x)= *Root(2-x^2) if -root(2)<=x<=1
*x^2 + ax + b if x>1
has derivative at 1
I got that the condition for this graph to be continous at 1 is a+b=0
And I moved to check out the derivative stuff:
When x->1+, the derivative is 0
But when 1->1-, igot stuck:
lim (x->1+) of [f(x)-f(1)]/(x-1) = lim (x->1+) of [x^2+ax+b-1]/(x-1)] (from the function at my first post, I got that when x>1, f(x)=x^2+ax+b) How can I figure out the relation between a and b so that I can put it and the one above to an equation?
Help me please, thanks!

Answers and Replies

HallsofIvy
Science Advisor
Homework Helper
What are you expecting? People to answer your question within a few minutes?

Sorry, mein Fehler

Very sorry. I though there are many guys here in the forums. sorry alot!