Implicit differentiation Definition and 279 Threads

I am reading several books on multivariable analysis/calculus and am trying to get a precise and rigorous theoretical understanding of implicit differentiation, including the Implicit Function Theorem ... in particular I am reading: Vector Calculus (Second Edition) by Susan Colley and...

I unfortunately keep on getting the wrong answer to this problem. I am supposed to find: dw/dy(1/(w^2+x^2)+1/(w^2+y^2)) I attached a picture of how I tried to solve it. Help would be much appreciated.

< Moderator Note -- Thread moved from the technical PF Calculus forum > I can't seem to grasp the idea of this problem, any help is much needed. The problem reads, "As a spherical raindrop falls, it reaches a layer of dry air and begins to evaporate at a rate that is proportional to its...

Given that $y'=\frac{tan(y)}{1-xsec^2(y)}$, find y'' in terms of $x$ and $y$ only. I've done this and checked my work several times but my answer does not agree with wolfram alpha. Sorry for not posting my work, I am a bit busy at the moment. Can someone show the first couple of lines of work...

Can someone please explain how the result is obtained from the first line $r^2 = y^2 + x^2$ (refer to attached image)

Homework Statement (The fourth equation is the central one) first, we have \frac{1}{r}=\frac{a}{b^2}(1+ecosθ) and b^2=a^2(1-e^2) now using these two, we transform acosψ=ae+rcosθ into (1-ecosψ)(1+ecosθ)=\frac{b^2}{a^2} we want to find dθ/dψ, and the author performs an inplicit...

Say you want to find the slop of a tangent line of the circle x^2+y^2=25 I was following the directions here. I don't completely understand how the derivative of y^2 becomes 2y\frac{dy}{dx}. Shouldn't it become 0 if we are taking the derivative with respect to x? The website explains but to me...

Definition/Summary The definition of a function y of x is explicit if it is an equation in which y appears only once, and on its own (usually by starting "y ="). In any other case, the definition of a function y of x is implicit. Implicit differentiation of y with respect to x is a...

Homework Statement Differentiate using implicit differentiation y^2sin(x) Homework Equations I know you need the chain rule and the product rule to solve this The Attempt at a Solution So, it would be: 2yy' + y^2cos(x) Is that correct?

Homework Statement Find the derivative of: x+xy=y^2 Homework Equations So I know you have to differentiate it, and it would be: 1+xyy'=2yy' The Attempt at a Solution Moving the terms with y' to one side: 1+xyy'-2yy'=0 xyy'-2yy'=-1 Factoring out y'...

Hi, I have x =(x^2+y^2)^[1/2] I differentiate 1= 1/2 (x^2+y^2)[-1/2] (2x+2yy') So far so good. I try to multiply this out. 1= (2x)/2 (x^2+y^2)[-1/2] + (2yy'/2)(x^2+y^2)[-1/2] I solve for y' y'= 1/{(x (x^2+y^2)[-1/2]} / {y(x^2+y^2)[-1/2] } 1/x (x^2+y^2)[1/2] * 1/y (x^2+y^2)[1/2] The...

Homework Statement Hello, I missed the class where we were introduced to implicit differentiation so have been catching up this evening. I think I have it, but please could you check my working? Thanks! Find the derivative of y2 = 2x + 1 \frac{d}{dx}([f(x)]^{2}) = \frac{d}{dx}([2x])...

Homework Statement The spherical head of a snowperson is melting under the HOT sun at the rate of -160 cc/h (cubic centimetres per hour.) Find the rate at which the radius is changing when the radius r=16. Use cm/h for the units. (The volume of a sphere is given by V= 4π⋅r^3/3.) I have...

find dy/dx: exy+x2+y2= 5 at point (2,0) I'm confused with finding the derivative with respect to x of exy. this is what I did so far for just this part: exy*d(xy)/dx exy*(y+x*dy/dx) do I need to put the parentheses on here? I thought so because that is the part where I used the product rule...

Here are the questions: I have posted a link there to this topic so the OP can see my work.

John's question at Yahoo! Answers regarding implicit differentiation & horizontal/vertical tangents Here is the question: I have posted a link there to this topic so the OP can see my work.

Use implicit differentiation to find dy/dx given x^2y+xy^2=4. I have no idea how to approach this problem. My instructor assigned this as homework but has not gone over it at all in class. We have gone over explicit differentiation and I understand this well. I have read the section but it is...

Homework Statement Determine y'' when 5x^2 + 3y^2 = 4. The Attempt at a Solution So I found the first derivative using the power rule and chain rule, 10x + 6yy' = 0 Which I then solved for y', y' = -10x/6y = -5x/3y Next I found the second derivative using quotient rule...

Homework Statement Let F: x^2 + y^2 - z^2 + 2xy - 1 = 0 and G: x^3 + y^3 - 5y - 4 = 0. Calculate dz/dx. Note: This is NOT the partial derivative ∂z/∂x. I do not need help in taking the derivative of many polynomials. What I need help in is setting up a Jacobian determinant to evaluate this...

Hi, I was trying to understand why the chain rule is needed to differentiate expressions implicitly. I began by analyzing the equation used by most websites I visited: e.g. x2+y2 = 10 After a lot of thinking, I got to a reasoning that satisfied me... Here it goes: From my...

So, I understand that implicit differentiation involves derivatives in which x values and y values are mixed up. I've done several implicit differentiation problems a couple sections ago for my math homework, but I pretty just memorized patterns and solved it that way. Now that I'm trying to...

Here is the question: Here is a link to the question: Derive Trig Function? - Yahoo! Answers I have posted a link there to this topic so the OP can find my response.

Homework Statement Use implicit differentiation to find y' given y/(x-y) = x^2+1.Homework Equations The Attempt at a Solution Hi, I'm doing an online course for Calculus 12, and I have been struggling with Implicit Differentiation. I am hoping someone could maybe help me. Thanks. I'm not...

Hi, I'm doing an online course for Calculus 12 and I have been struggling with Implicit Differentiation, hoping someone could maybe help me. Thanks. I'm not positive I'm doing this right but maybe someone can point me in the right direction, this is what I have so far y/(x-y) = x^2+1...

Homework Statement For the curve x2+3xy+y2 = 5 show that \frac{dy}{dx} =- \frac{2x+3y}{3x+2y} Homework Equations N.A. The Attempt at a Solution 2x + 3xy + 2y\frac{dy}{dx} = 0 3x + 2y \frac{dy}{dx} = -2x+ 3y ∴ \frac{dy}{dx} =- \frac{2x+3y}{3x+2y} have I done this correctly?

Homework Statement e^y = x(y-1) answer must be in implicit form Homework Equations The Attempt at a Solution I literally have no idea how to do this problem. I have the answer, but that's it. The answer is dy/dx(e^y) = x(dy/dx) + y - 1

So, as the title may have given away, I'm trying to figure out implicit differentiation in the multiple variable context. I thought a good practice would be the law of cosines, aka c^2 = a^2 + b^2 - 2abcosθ. So I'm trying to find ∂θ/∂a, ∂θ/db, ∂θ/dc. I tried solving for θ and then taking...

Homework Statement Use implicit differentiation to find an equation of the tangent line to the curve at the given point. x^2+y^2=(2x^2+2y^2-x)^2 @ (0,(1/2)) Homework Equations The Attempt at a Solution So, I don't have a problem differentiating this. Which I get...

Homework Statement Calculate the derivative with respect to x: x/y + y/x = 2yHomework Equations n/a The Attempt at a Solution I end up getting the right answer, but what I want to know is how to isolate dy/dx to one side after implicitly differentiating. I have tried differentiating the LHS...

Homework Statement The P(a,b) be a point on the curve √x + √y = 1. Show that the slope of the tangent P is -√b/a Homework Equations ? The Attempt at a Solution Apparently this is an implicit differentiation problem, however we haven't learned or discussed implicit...

Say you have x^2+y^2=100. why can't you just solve for y, so y=+- √(100-x^2) then use the chain rule to find the derivative. so y'= +- x/√(100-x^2). Then you can just deduce that y'= -x/y. What is the point of adding all the dy/dx in the equation? Seems like it just complicates it.

Hello! As of right now (10:13 PM), I've tried 9 combinations of points to solve this problem. It's a WebWork-based problem that's due in about an hour in a half. Any help would be very, very appreciated. Homework Statement I was given this equation: ##ln(2y) = 2xy## and was asked to find...

Homework Statement I'm reviewing physics using Feynman's Lectures, and I'm finding that he frequently uses implicit differentiation in his lessons. This is unfortunate for me because I never got the hang of it beyond the simplest cases. I'm currently going through the proof that the...

Homework Statement Use implicit differentiation to find dy/dx. Homework Equations xey - 10x + 3y = 0 The Attempt at a Solution = [xey + ey(y)'] - (10x)' + (3y)' = 0 = xey + ey(y') - 10 + 3(y') = 0 = y' (ey + 3) = 10 - xey = y' = 10 - xey/ ey + 3y However, my book says the answer: 10 -...

Homework Statement The equations ##2x^3y+yx^2+t^2=0##, ##x+6+t-1=0## implicitly define a curve $$f(t) = \begin{pmatrix} x(t)\\y(t) \end{pmatrix}$$ that satisfies ##f(1)=\begin{pmatrix} -1\\1 \end{pmatrix}.## Find the tangent line to the curve when ##t=1##. Homework Equations The...

Homework Statement I have a question. How in general would one differentiate a composite function like F(x,y,z)=2x^2-yz+xz^2 where x=2sint , y=t^2-t+1 , and z = 3e^-1 ? I want to find the value of dF/dt evaluated at t=0 and I don't know how. Can someone please walk me through this?Homework...

Equation: eysinx=x+xy I took the derivative of both sides. For the side with eysinx, I used the product rule and chain rule to get: ey*cosx + ey*sinx*y' For the side with x+xy, I used the sum and product rule to get 1+y+xy' So my resulting equation is: ey*cosx + ey*sinx*y'=1+y+xy', which...

1. Given that y^{2}-2xy+x^{3}=0, find \frac{dy}{dx} 2. (no relevant equations other than the problem statement) 3. So, I solved it like this, \frac{dy}{dx}y^{2}-2xy+x^{3}=0 2y\frac{dy}{dx}-2+3x^{2}=0 Solving for dy/dx I got... \frac{dy}{dx}=\frac{-3x^{2}+2}{2y}...

Okay so, I am having trouble figuring out what exactly to do in implicit differentiation and usage of the chain rule. Like, I keep getting the wrong answer somehow. See, from what I understand you have to find the derivative of both sides then use the chain rule or something and then solve for...

Hello, I have recently started a little implicit differentiation and I have seen DEs before but I know that I still need to work on my differentiation and integration a little more before I am ready to tackle those. Anyway, I wish to ask, what distinguishes implicit differentiation from a...

Homework Statement I need to use implicit differentiation to find the derivative of y=sin(x+y). Homework Equations The Attempt at a Solution This is what I did: y=sin(x+y) y'=(sin(x+y))' y'=(1+y')(cos(x+y)) (by the chain rule) Now, what do I do? Is this correct...

1. y = sinxy Homework Equations 3. this was my attempt d/dx = (cosxy)(sinxy(d\dx))+(xy(d/dx) im getting stuck. i don't think I am starting it right. any suggestions.

Homework Statement I'm try to implicitly differentiate the function: xlny+√y=lnx The Attempt at a Solution And I got to the stage where I have: dy/dx = (1/x-lny)/(x/y+1/(2*√y)) which is where I have no idea on how to clean this up. Could someone please explain to me how to simplify a...

Homework Statement Find an equation of the tangent line to x^3 + y^3 - 6xy = 0 at the point ((4/3), (8/3)) Homework Equations I got y = -(8/5)x + (24/5). Is this correct? The Attempt at a Solution Lots of algebra involved. Sorry. but I'd rather not type it. I take the derivative of...

Homework Statement Find dy / dx for sqrt(xy) = x - 2y. Homework Equations I don't know how to simplify [(xy' + y) / 2sqrt(xy)] = (1 - 2y') to y' = [- y + 2sqrt(xy)] / [x + 4sqrt(xy)]. The Attempt at a Solution I do everything Wolfram Alpha does here...

I am reading about this topic, and I came across this sentence "Remember, every time we want to differentiate a function of y with respect to x, we differentiate with respect to y and then multiply by dy/dx." What exactly does this mean?

Homework Statement u = x^u + u^y Find the partial derivatives of ##u## w.r.t. ##x, y##.Homework Equations Only the one. The Attempt at a Solution I've attempted reducing the problem using logs, but the resulting equations seem no more tenable to me. I'm sure there is a nice trick... it...

Homework Statement Find dy/dx in terms of x and y if.. x2-√(xy)+y2=6 Homework Equations The Attempt at a Solution so I started by.. x2-√(xy)+y2=6 deriving the LHS 2x+2y(dy/dx)-1/2(xy)-1/2(1(y)+x(dy/dx)) Simplifying the last term...

Homework Statement use implicit differentiation to find an equation of the tangent line to the curve a the given point. y^2(y^2-4) = x^2(x^2-5) at (0,-2) Homework Equations y^2(y^2-4) = x^2(x^2-5) The Attempt at a Solution I got dy/dx to be (3x^2-10x)/(4y^3-8y) but...

Hello. I know how to do implicit differentiation taught in calculus 1, but I'm confused by something regarding it. Take the example: y3+y2-5y-x2=4 If we do implicit differentation we get: 3y2(dy/dx)+2y(dy/dx)-5(dy/dx)-2x=0 dy/dx=2x/(3y2+2y-5) Now, it makes sense how to...