Posted by **Anonymous** on Sunday, November 18, 2007 at 12:30am.

Can you check my answer?

Solve the separable differential equation: dy/dx=(sqrt(x))/2y

y=(2/3)x^(3/4)

Let f be the function given by f(x)=x^3-5x^2+3x+k is a constant.

a) On what intervals is f is increasing? (-oo,1/3), (3,oo)

b) On what intervals is the graph of f concave downward? (-oo,10/9)

c)Find the value of k for which f has 11 as its relative maximum.

I am not sure on this one. Here is what I think I would start this one:

11=x^3-5x^2+3x+k What would I plug in for x?