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20-Turquoise
October 26, 2018
Solved

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

  • October 26, 2018
  • 2 replies
  • 1546 views

Hello Everyone.

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

3.PNG

Thanks in advance.
Regards.

Best answer by Werner_E

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.

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.