common factor reduction

• Subject: common factor reduction
• From: Marco Frigerio
• Date: Tue, 24 Jan 2012 11:00:06 +0100

Hi all,

consider this

(%i..) trigreduce( -A*cos(q1)*sin(q2)  +  A*sin(q1)*cos(q2) );
(%o..)                         - sin(q2 - q1) A

Why I cannot do the same thing if instead of a variable like 'A' I have 
a numerical constant?

(%i..) trigreduce( -4*cos(q1)*sin(q2)  +  4*sin(q1)*cos(q2) );

           sin(q2 + q1)   sin(q2 - q1)       sin(q2 + q1)   sin(q2 - q1)
(%o..) 4 (------------ - ------------) - 4 (------------ + ------------)
                2              2                  2              2

I would really like to see
    - sin(q2 - q1) 4

How can I achieve this?

Thanks a lot
Regards,
  MF

• Prev by Date: How to prevent the immediaetly evaluation after substitute a variable
• Next by Date: Make check failures
• Previous by thread: common factor in a list or array
• Next by thread: common factor reduction
• Index(es):
  • Date
  • Thread