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20150326 22:10:10 0600  marked best answer  Solving linear matrix equations Hi everybody, I'm new to Sage and I'm pretty confused with the solving of matrix equations, I didn't fully understand the guide. I've got these vectors: And i want to implement the equation: to isolate and obtain the value of How can I do that? Thank you very much 
20150114 03:41:20 0600  commented answer  Transpose of a column vector Thank you for your reply. May I ask you what is the difference between a list and a vector? 
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20150112 16:17:55 0600  commented answer  Transpose of a column vector

20150112 12:04:10 0600  asked a question  Transpose of a column vector Hi, I've got a column vector and I need to transpose it. But when i do:
I've also tried doing What is the problem here? Thank you 
20150112 06:57:17 0600  commented answer  Derivative of a function Thank you so much!! 
20150112 05:52:24 0600  asked a question  Derivative of a function Hi, I've got this two functions: but it says No differentiation variable specified how can I derivate psi? Please someone help me it's driving me crazy since yesterday! Thank you very much 
20150111 15:34:34 0600  commented answer  Equations solving Now the problem is that when i do What's wrong? 
20150111 15:29:02 0600  commented answer  Equations solving Ok i got it, i just had to write 
20150111 15:25:55 0600  commented answer  Equations solving I redefined eqq1, but doing like this it ignores the left part of the equation, so eqq1 becomes just sin(delta(t))*v/cos(delta(t)) 
20150111 14:27:36 0600  commented answer  Equations solving It works! Grazie mille! ;) Now i substituted that value in the second equation doing
but when i do
it gives me diff(psi(t))=V_f*sin(delta(t))/l like i never did that substitution before. What can i do to have diff(psi(t))=[v(t)*tan(delta(t))]/l as a solution? 
20150111 13:16:36 0600  asked a question  Equations solving Hi everybody, i've got this two equations: I need to isolate V_f from the first equation, obtaining V_f=v(t)/cos(delta(t)) and substitute it in the second equation. Then i have to isolate diff(psi(t))=[v(t)*tan(delta(t))]/l. I did : but it says "AttributeError: 'Sequence_generic' object has no attribute 'right'" How can i solve this two equations? Thank you. 
20141223 03:49:24 0600  edited question  Sum of two vectors Hi everybody, i've got this functions and variables: where R is a matrix and a_V_ra is the vector [cos(psi(t))v(t), sin(psi(t))v(t),0]. But when i do this: it says: TypeError: unsupported operand parent(s) for '+': 'Full MatrixSpace of 3 by 1 dense matrices over Symbolic Ring' and 'Vector space of dimension 3 over Symbolic Ring' I guess it's saying that i'm summing a matrix and a vector, but they're both vectors! What can I do to make it work? Thank you. 
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