Find dy/dx by Substituting r for y and Theta for x | Simple Implicit Problem

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SUMMARY

The discussion focuses on finding the derivative dy/dx for the equation r = x^2 tan(2x) by substituting r for y and theta for x. The initial attempt incorrectly applies the product rule and chain rule, leading to an erroneous result of dy/dx = 4x sec^2(2x). The correct approach requires the application of the product rule to differentiate the product of x^2 and tan(2x), ensuring accurate results in calculus.

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Minihoudini
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Homework Statement


substituting r for y and theta for x as it will be easier to read

find dy/dx if r=x^2 tan(2x)

I don't know the answer

Homework Equations





The Attempt at a Solution



d/dx (y) = d/dx [x^2 tan(2x)]

dy/dx = dx/dx [2x] d/dx [tan (2x)]

dy/dx = 2x sec^2 (2x) (2)

dy/dx = 4x sec^2 (2x)

its wrong though
 
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Minihoudini said:

Homework Statement


substituting r for y and theta for x as it will be easier to read

find dy/dx if r=x^2 tan(2x)

I don't know the answer

Homework Equations





The Attempt at a Solution



d/dx (y) = d/dx [x^2 tan(2x)]

dy/dx = dx/dx [2x] d/dx [tan (2x)]
The line above is wrong. x^2 * tan(2x) is a product, so you need to use the product rule. You are using the chain rule correctly, below.
Minihoudini said:
dy/dx = 2x sec^2 (2x) (2)

dy/dx = 4x sec^2 (2x)

its wrong though
 

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