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5-Regular Member
June 7, 2025
Solved

How do I solve trigonometric equations with Mathcad 15?

  • June 7, 2025
  • 1 reply
  • 556 views

Hello,

I would like to be able to solve trigonometric equations with Mathcad 15, but I can't.

Example:

What is x if cos(x) ≤ 1/2?

Can someone tell me how to do this?

Thanks in advance.

Richard

Best answer by Werner_E

@ptc-4127093 wrote:

Hello,

I would like to be able to solve trigonometric equations with Mathcad 15, but I can't.

Example:

What is x if cos(x) ≤ 1/2?


What you show is not an equation but rather an inequation 😉

 

Mathcad 15 can happily solve the equation and you may use the "assume" modifier to limit the result to a certain range

Werner_E_0-1749295162562.png

but MC15 fails at the inequation. Adding "assume" constraints doe not help. The error message is "No solution found".

Werner_E_2-1749295255014.png

We would expect something like 

Werner_E_3-1749295448849.png

but Mathcads symbolic engine seems not to be capable enough to come up with this answer.

This does not mean that Mathcad can't solve inequations at all, simply that yours look to be too tough for Mathcad.

Werner_E_4-1749295752279.png

 

BTW, Wolfram Alpha does a better job:

Werner_E_6-1749296041398.png

 

 

 

 

 

1 reply

Werner_E25-Diamond IAnswer
25-Diamond I
June 7, 2025

@ptc-4127093 wrote:

Hello,

I would like to be able to solve trigonometric equations with Mathcad 15, but I can't.

Example:

What is x if cos(x) ≤ 1/2?


What you show is not an equation but rather an inequation 😉

 

Mathcad 15 can happily solve the equation and you may use the "assume" modifier to limit the result to a certain range

Werner_E_0-1749295162562.png

but MC15 fails at the inequation. Adding "assume" constraints doe not help. The error message is "No solution found".

Werner_E_2-1749295255014.png

We would expect something like 

Werner_E_3-1749295448849.png

but Mathcads symbolic engine seems not to be capable enough to come up with this answer.

This does not mean that Mathcad can't solve inequations at all, simply that yours look to be too tough for Mathcad.

Werner_E_4-1749295752279.png

 

BTW, Wolfram Alpha does a better job:

Werner_E_6-1749296041398.png

 

 

 

 

 

5-Regular Member
June 7, 2025

Thank you very much for your help !

 

Richard