krismalo

70 Reputation

4 Badges

7 years, 319 days

MaplePrimes Activity


These are questions asked by krismalo

Hello! with the datapoints below I've calulated the results "manually" 
I'm looking for a way to make Maple tell me the intersection of these datapoints with the x-axis and also, the area under it from e.g. 0 to 5.125, which i've also had to calculate by hand... I know I can use int comand to do this, but I think there is a lot wrong with the syntax, so after hours of failure I hope someone can show me the right commands..

 

Thanks, 
krismalo
 

 

 

t1 := Matrix(14, 2, {(1, 1) = 0, (1, 2) = 0, (2, 1) = 0, (2, 2) = 4170, (3, 1) = 1, (3, 2) = 3966, (4, 1) = 1, (4, 2) = 3466, (5, 1) = 3, (5, 2) = 3058, (6, 1) = 3, (6, 2) = 3058, (7, 1) = 4, (7, 2) = 1854, (8, 1) = 4, (8, 2) = 1354, (9, 1) = 7, (9, 2) = -2258, (10, 1) = 7, (10, 2) = -2758, (11, 1) = 8, (11, 2) = -3962, (12, 1) = 8, (12, 2) = -3962, (13, 1) = 10, (13, 2) = -4370, (14, 1) = 10, (14, 2) = 0})plot(t1); =  

 

 

The intersection of this plot with the x-axis should be ≈ 5.125 and the area from 0 to 5.125 (or from 5.125 to 10) should be ≈ 13810

 

 

 

 

NULL


 

Download primes_area_question.mw


Hello! 

I'm trying to plt something, I can't see why Maple isn't multiplying these two rows as it should. 

Can anyone see the problem?

 

This preamble is loaded:

restart;

with(Units[Standard]);
with(ArrayTools);

with(LinearAlgebra);

with(Statistics);
with(plots);
with(CurveFitting);

 

 

 

 

 

with(plots):

with(LinearAlgebra):

 

asd := [3.5400000*10^5, 3.4700000*10^5, 3.3700000*10^5, 3.2700000*10^5, 3.1700000*10^5, 3.0900000*10^5, 3.0300000*10^5, 2.9600000*10^5, 2.9200000*10^5, 2.8900000*10^5, 2.8600000*10^5, 2.8500000*10^5, 2.8200000*10^5, 2.8100000*10^5, 2.7900000*10^5, 2.7800000*10^5, 2.7800000*10^5, 2.7700000*10^5, 2.7600000*10^5]:
 

NULL

asf := [0.2866400798e-1, 0.6112772793e-1, 0.9946549241e-1, .1349950150, .1645923341, .1877395591, .2054364684, .2189514789, .2293646837, .2374847679, .2439099369, .2490583805, .2532402792, .2566744211, .2595269747, .2619197962, .2639470478, .2656751966, .2671596322]:

 

asd*asf;

[354000.0000, 347000.0000, 337000.0000, 327000.0000, 317000.0000, 309000.0000, 303000.0000, 296000.0000, 292000.0000, 289000.0000, 286000.0000, 285000.0000, 282000.0000, 281000.0000, 279000.0000, 278000.0000, 278000.0000, 277000.0000, 276000.0000]*[0.2866400798e-1, 0.6112772793e-1, 0.9946549241e-1, .1349950150, .1645923341, .1877395591, .2054364684, .2189514789, .2293646837, .2374847679, .2439099369, .2490583805, .2532402792, .2566744211, .2595269747, .2619197962, .2639470478, .2656751966, .2671596322]

(1)

 

NULL

 

Thank you!

Download maple_what.mw

 

As you can see on the picture, the numeric formatting is set to enginnering with 3 decimals, but it is now separated with a comma, so when I copy this answer to further calculate something, it will read it as a list, and it will give an error.

I have no Idea how this suddenly changed, its usually a period and there is no problem.

This is probably an asy fix, but I can't find any options for this.

Im running windows 10, and Im in Denmark.

Hello guys and gals!

I'm not strong enough with maple to get what the result I want.

It seems that it's because I'm asking for two lenths, and not a lenth and an angle, but I have no Idea how to tackle it diferently.

If you know a trick, please share it!

 

Here's an image:

http://imgur.com/xavAUoB

And here's the maple file attached (I think)

 complex_problem_from_the_internet.mw

Thanks,

Happy new year!

Hello!

 

If I type this into a CAS calculator from Texas, I get the right result for Uc wich is 545.2.

solve(Uc∠-90=400∠X-150∠0+j*174.4,Uc,X)

This is used in AC circuits.

However, in Maple I'm using polar coordinates, so Im using this preamble:

phasor := proc (r, theta) options operator, arrow; r*cos(convert(theta*degrees, radians))+I*r*sin(convert(theta*degrees, radians)) end proc

This basically means that I can write phasor(value,angle in degrees) and get the lenth and angle of a vector on the complex plane.

Basically I want to know how I can make Maple solve this:

evalf(solve({phasor(U__C, -90) = phasor(400, X)-phasor(150, 0)+phasor(174.4, 90)}, {Uc, X})) Where I'm just interested in U_C , X doesn't matter.

I can't figure out how to do this with my current preamble. Does anyone know how to make this work?

1 2 3 Page 1 of 3