Homework Statement
find dy/dx for the function xy^2+xlnx=4y for x>o
Homework Equations
xy^2+xlnx=4y
The Attempt at a Solution
I found the dy/dx to be "(y^2+lnx+1)/(4-x)=dx/dy"
What is it asking me to do with the x>0? Do they want me to plug in a value greater than 0 for x and solve for y...
Homework Statement
I need to find the max/min of y=(1)/(3+x^2)
Homework Equations
y=(1)/(3+x^2)
The Attempt at a Solution
I tried to find the derivative; y'= (3+x)^-2(1) = -2(3+x)^-3 = -2/(3+x)^3 or -2/3(3+x)^2?
Whats wrong with it?
Homework Statement
Find the critical point of f(x)=(-5x^2+3x)/(2x^2-5), and show whether this point is a max/min.
Homework Equations
f(x)=(-5x^2+3x)/(2x^2-5)
The Attempt at a Solution
When I tried solving for the derivative of; f(x)=(-5x^2+3x)/(2x^2-5), I got...