- #1
Nguyen Thanh Nam
- 14
- 0
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 continuous 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!
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 continuous 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!
