Bug in converting complex numbers?

07032018, 08:01 AM
Post: #1




Bug in converting complex numbers?
Hi
I have tried to convert a complex number in the style of 100*exp(60 Deg) Usually they should be converted to something like: 100*(cos(60)+i*sin(60)) = 50+86.6*i But the Prime converts the expression 100*exp(60 Deg) to 95.24  30.48*i This is a strange behaviour to me. Do i have to enter the complex number in an other way? Or is this a software bug? Attached a picture Thank 

07032018, 08:17 AM
(This post was last modified: 07032018 08:19 AM by blevita.)
Post: #2




RE: Bug in converting complex numbers?
I have tested this behaviour a little bit more.
It looks like there is a serious bug in the Prime. If i extract the RE part within the CAS it gives me the correct value of 50. If i extract the exact same thing withing the Calculator it gives me 95. If i approx the value within the CAS, also the CAS fails to convert correctly! Take a look at the pictures. 

07032018, 08:59 AM
(This post was last modified: 07032018 09:03 AM by sasa.)
Post: #3




RE: Bug in converting complex numbers?
I do not have a Prime, however, this sems to be a problem misrepresenting input is in degree or radian and further result representation.
Do you have to set independently degree and radian for each calculator mode (HOME/CAS)? If you check manually, you will see that second result is correct if numbers are expected in radian: sin(60)=0,3048106211 and so on. 

07032018, 09:03 AM
(This post was last modified: 07032018 09:07 AM by blevita.)
Post: #4




RE: Bug in converting complex numbers?
(07032018 08:59 AM)sasa Wrote: Do you have to set independently degree and radian for both calculator modes (HOME/CAS)? Ok interessting. I have set the CAS and calculator to Degrees. You can see this also on the top right corner where you see the green Dregree symbol. I have also swithed to radians without success. But you are right. If i enter radians, the answer is correct. Thanks for your quick response! 

07032018, 09:11 AM
(This post was last modified: 07032018 09:13 AM by sasa.)
Post: #5




RE: Bug in converting complex numbers?
Notice that x in exp(x) is not expected to be an angle, thus you have to do conversion manually.


07042018, 11:04 AM
Post: #6




RE: Bug in converting complex numbers?
In general, trig functions on the Prime interpret any complex number as being in radians. For example, in degrees mode sin(30) is 0.5, but sin (30+0*i) is 0.988, even when a degrees sign is added after the "30".
I believe this is standard practice on calculators that support trig and exponential functions with complex arguments, so it should be viewed as a feature, not a bug! Nigel (UK) 

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