Find equation of tangent line of tan(xy^2)=(2xy)/pi (implicit diff.)

In summary, the equation of the tangent line of tan(xy2)=(2xy)/\pi at (-\pi,1/2) can be found by implicit differentiation and substituting for the given point, resulting in the slope of (1-.5pi)/(2pi-2pi2). This may seem complicated, but it has been confirmed as correct.
  • #1
tachyon_man
50
0

Homework Statement



Find the equation of the tangent line of tan(xy2)=(2xy)/[itex]\pi[/itex] at (-[itex]\pi[/itex],1/2)

Homework Equations


The Attempt at a Solution



I managed to get the equation into its dy/dx form and for the slope to be (1-.5pi)/(2pi-2pi2)
This seems far to complicated to be correct though.. can someone confirm this?
 
Last edited:
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  • #2
kylem1994 said:

Homework Statement



Find the equation of the tangent line of tan(xy2)=(2xy)/[itex]\pi[/itex] at (-[itex]\pi[/itex],1/2)

Homework Equations



The Attempt at a Solution



I managed to get the equation into its dy/dx form and for the slope to be (1-.5pi)/(2pi-2pi2)
This seems far to complicated to be correct though.. can someone confirm this?
Please show your result for implicit differentiation prior to substituting for the given point. I get something different for y' at that point, but it's similarly complicated.
 
  • #3
Here's what I got, dy/dx = [y2(pi)sec2(xy2)-2y]/[(2x)(1-y(pi)sec2(xy2)]
 
  • #4
kylem1994 said:
Here's what I got, dy/dx = [y2(pi)sec2(xy2)-2y]/[(2x)(1-y(pi)sec2(xy2)]
I checked your (implicit) differentiation and the value of the derivative at (-π, 1/2) with WolframAlpha, and it agrees with your results totally.
 
  • #5
SammyS said:
I checked your (implicit) differentiation and the value of the derivative at (-π, 1/2) with WolframAlpha, and it agrees with your results totally.

That's always good to hear :p So my slope I found is most likely right? Even tho its a mess to look at?
 
  • #6
kylem1994 said:
That's always good to hear :p So my slope I found is most likely right? Even tho its a mess to look at?
Yes, I'm quite sure that it's correct.
 
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  • #7
Ok, thank you !
 

1. What is implicit differentiation?

Implicit differentiation is a technique used in calculus to find the derivative of an equation that is not explicitly written in terms of one variable. In this case, the equation is in terms of both x and y, so we use implicit differentiation to find the derivative with respect to x.

2. How do you find the derivative of tan(xy^2)?

To find the derivative of tan(xy^2), we use the chain rule. First we take the derivative of the outer function, which is tan(u), where u=xy^2. This gives us sec^2(xy^2). Then we multiply by the derivative of the inner function, which is y^2. So the final derivative is 2xysec^2(xy^2).

3. What is the equation of the tangent line at a specific point?

The equation of the tangent line at a specific point can be found by plugging the x and y values of the point into the derivative we found in the previous step. This will give us the slope of the tangent line. Then, using the point-slope form of a line, we can find the equation of the tangent line.

4. Can we find the equation of the tangent line at any point on the curve?

Yes, we can find the equation of the tangent line at any point on the curve by following the steps outlined in the previous two questions. However, it is important to keep in mind that the equation of the tangent line will change depending on the point chosen.

5. Why do we use implicit differentiation in this problem?

We use implicit differentiation in this problem because the equation is not explicitly written in terms of one variable. This makes it impossible to use the standard techniques for finding the derivative, such as the power rule or product rule. Implicit differentiation allows us to find the derivative of equations that are more complex and involve multiple variables.

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