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ptc-54520111-Visitor
1-Visitor
February 20, 2014
Question

Getting error "Cannot understand this syntax"

  • February 20, 2014
  • 2 replies
  • 4404 views

Using PTC MathCAD Prime 3.0

I am trying to evaluate symbolically the derivative of the following equation:

f(x):=200 sin (2 x)

And when I evaluate this derivative f'(x)... I get the error: "Cannot understand this syntax"

I have figured out that by simply adding a decimal point to the value 200, like this...

f(x):=200.0 sin (2 x)

I then get the answer > 400.0 cos(2x) which is what I expect.

Can someone explain why MathCAD is expecting a decimal in the multiplier value and why it wouldn't work with just 200?

Thanks,

Eric Landry

2 replies

W
Werner_E25-Diamond I
25-Diamond I
February 20, 2014

I would call this a bug in Prime and you may consider reporting it to PTC.

While writing 200.0 cures it, it seems to be the multiple of x in the function whuch makes is fail. The full operator is working fine, though.

20.02.png

Remark: The error in the second line expression is OK - its thrown by the numerics as of omega being unknown and doesn't affect the symbolics.

W
Werner_E25-Diamond I
25-Diamond I
February 20, 2014

Here is another curious example which shows a difference between the prime and the differentiating operator. It looks like the prime operator (which was not available for those purposes in Mathcad 15 an below) is not yet fully stable and mature.

21.02.png

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