Alright I decided I'd create a new topic just because the other one was getting fairly lengthy.(adsbygoogle = window.adsbygoogle || []).push({});

I'm having trouble with the following "Higher Derivative" question

It states, find y'' by implicit differentiation.

x^4 + y^4 = a^4

d/dx (x^4+y^4) = d/dx (a^4)

4x^3 + 4y^3 dy/dx = 4a^3

However, what is the next step from here, I thought perhaps cancelling out all the 4's and leaving it as:

x^3 + y^3 dy/dx = a^3

and bring the x^3 over so it's:

a^3-x^3 = y^3 dy/dx

dy/dx = a^3-x^3 / y^3

However, I'm not positive on that because I was told from a friend that 4a^3 is a constant so it can be equal to 0, thus the dy/dx would be -x^3/y^3.

Am I on the right track here or is there an easier way of solving this equation. Thanks a lot guys.

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# Homework Help: Higher Derivative Question

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