Implicit Differentiation: two different answers

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Implicit differentiation can yield different results based on the approach taken. To resolve discrepancies, it's suggested to take the natural logarithm of both sides of the equation before differentiating. This method can help clarify the steps leading to the second answer. Proper rearrangement of the resulting expression is crucial for consistency in answers. Understanding these steps can alleviate confusion and ensure accurate results in implicit differentiation problems.
funlord
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Homework Statement



upload_2015-8-12_21-14-47.png

with answers given:

upload_2015-8-12_21-15-58.png

Homework Equations


use implicit differentiation

The Attempt at a Solution


I always get this answer

upload_2015-8-12_21-17-54.png

but not the second one

PLs explain the second answer for I am very desperate.
Thank You
 

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Use what you begin with i.e. ##(x-y)^3 = (x+y)^2## inside the expression you get from implicit differentiation

Show your steps
 
funlord said:

Homework Statement



View attachment 87235
with answers given:

View attachment 87236

Homework Equations


use implicit differentiation

The Attempt at a Solution


I always get this answer

View attachment 87237
but not the second one

PLs explain the second answer for I am very desperate.
Thank You
Please state the entire problem.
 
funlord said:

Homework Statement



View attachment 87235
with answers given:

View attachment 87236

Homework Equations


use implicit differentiation

The Attempt at a Solution


I always get this answer

View attachment 87237
but not the second one

PLs explain the second answer for I am very desperate.
Thank You

In order to get the second answer, you need to take the ln of both sides of the equation, then differentiate implicitly. After rearranging, if done right (presumably the second answer is correct), you should have the same answer.
 
Question: A clock's minute hand has length 4 and its hour hand has length 3. What is the distance between the tips at the moment when it is increasing most rapidly?(Putnam Exam Question) Answer: Making assumption that both the hands moves at constant angular velocities, the answer is ## \sqrt{7} .## But don't you think this assumption is somewhat doubtful and wrong?

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