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20-Turquoise
October 26, 2018
Solved

f(x) := x.cos(x) - sin(x) . Plotting local max-min-points ?

Hello Everyone.

f(x) := x.cos(x) - sin(x) . Plotting local max-min-points ?

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Thanks in advance.
Regards.

Werner_E
Werner_EAnswer
25-Diamond I
October 26, 2018

You expect different answers than here

https://community.ptc.com/t5/PTC-Mathcad/x-cos-x-sin-x-0-solve-x/m-p/578062/highlight/true#M183000 

ore here

https://community.ptc.com/t5/PTC-Mathcad/Plotting-local-max-min-points/m-p/578354/highlight/true#M183021

?

 

Put your math together! You have to find the zeros of the first derivative. Either symbolically or numerically. You have all the tools necessary at hand!

Simply exclude those where the second derivative is zero, too. To be mathematically more precise you should exclude those where the first derivative with non-zero value is of an odd degree.

2 replies

lvl10720-TurquoiseAuthor
20-Turquoise
October 26, 2018

And : x.cos(x) - sin(x) solve, x ==> 10 solutions.

Regards.

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Werner_E
Werner_E25-Diamond IAnswer
25-Diamond I
October 26, 2018

You expect different answers than here

https://community.ptc.com/t5/PTC-Mathcad/x-cos-x-sin-x-0-solve-x/m-p/578062/highlight/true#M183000 

ore here

https://community.ptc.com/t5/PTC-Mathcad/Plotting-local-max-min-points/m-p/578354/highlight/true#M183021

?

 

Put your math together! You have to find the zeros of the first derivative. Either symbolically or numerically. You have all the tools necessary at hand!

Simply exclude those where the second derivative is zero, too. To be mathematically more precise you should exclude those where the first derivative with non-zero value is of an odd degree.

Translate