# calculus

posted by
**lisa**
.

Let f be the function defined by f(x)= sqrt(x), 0 <or= x <or= 4. and f(x)= 6-x, 4 < x <or= 6

a. Is f continuous at x=4? justify.

b. Find the average rate of change of f(x) on the closed interval [0,6].

c. suppose the function g(x)= k sqrt(x), 0 <or= x <or= 4. and g(x)= mx+2, 4 < x <or= 6. where k and m are constants. find the values of k and m to make g differentiable at x=4? justify.