Posted by W on Tuesday, October 18, 2011 at 10:27pm.
The point (1,2) is on the graph of y^2x^2+2x=5. Find the value of (dy/dx) and (d^2y/dx^2) at the point (1,2). How do I find (d^2y/dx^2)? I found. I found (dy/dx) to be 2y(dy/dx)2x+2=0, but I don't know how to take the derivative of that to get(d^2y/dx^2)? I'm not sure if that is correct, but that's just my thinking. Also, how do i find if the graph has a relative min or max?

Calculus  Steve, Wednesday, October 19, 2011 at 10:36am
As you said, 2y(dy/dx)2x+2=0
So,
dy/dx = (2x2)/2y = (x1)/y
Noiw, just plug in the values:
y'(1) = (11)/(2) = 0
Check y''
2yy'2x+2=0
2(y')^{2} + 2yy''  2 = 0
y'' = (2  2y'^{2})/2y = (1y'^{2})/y = 1/2
Since y'' < 0 when y' = 0, it's a maximum.
Answer This Question
Related Questions
 AP AB Calculus  Linear approximation: Consider the curve defined by 8x^2 + 5xy...
 Calculus  I have a graph of f(x) which I cant post here, but would like some ...
 Calculus  Damon  Find the line which passes through the point (0, 1/4) and is ...
 calculus  let f be the function f(x) = x^3 + 3x^2  x + 2 a. the tangent to the...
 calc.  I'm having a lot of trouble with this problem: Sketch the graph and show...
 Calculus Part 2  y = tan(sqrtx) Find dy/dx. So I found it and I got the answer ...
 AP Calculus  Consider the curve given by x^2+4y^2=7+3xy a) Show that dy/dx=(3y...
 calculus  f(x)=?x3 ?x2 +16x+16 1. Calculate f?(x). 2. Calculate f??(x). 3. Find...
 Calculus  If 3x^22y^2=4xy + 20, find the point(s) at which the graph from ...
 Homework Help Calculus  Find the linear approximation L(x) to the function f(x...
More Related Questions