How solve this trigo system ?

09192017, 06:36 AM
Post: #8




RE: How solve this trigo system ?
(09182017 08:56 AM)ggauny@live.fr Wrote: cos x  cos y = 1/2Alternatively, from a different angle :), set x = p+q and y = pq so that we get 2sin(p)sin(q) = 1/2 (sin(p)cos(q) + cos(p)sin(q)) * (sin(p)cos(q)  cos(p)sin(q)) = 3/8 and eliminating cos^2 for sin^2 after simplifying the latter equation we get sin(p)sin(q) = 1/4 sin(p)^2sin(q)^2 = 3/8 This leads to a quadratic equation in sin(p)^2 and/or sin(q)^2, etc. So you can solve this exactly without the ugliness of dealing with a quartic.... 

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Messages In This Thread 
How solve this trigo system ?  ggauny@live.fr  09182017, 08:56 AM
RE: How solve this trigo system ?  Gerson W. Barbosa  09182017, 10:12 AM
RE: How solve this trigo system ?  ggauny@live.fr  09182017, 10:45 AM
RE: How solve this trigo system ?  Gerson W. Barbosa  09182017, 10:55 AM
RE: How solve this trigo system ?  Gerson W. Barbosa  09182017, 11:28 AM
RE: How solve this trigo system ?  Dieter  09182017, 12:46 PM
RE: How solve this trigo system ?  Dieter  09182017, 05:48 PM
RE: How solve this trigo system ?  AlexFekken  09192017 06:36 AM
RE: How solve this trigo system ?  Albert Chan  01312020, 10:48 PM
RE: How solve this trigo system ?  Dieter  09192017, 06:30 PM
RE: How solve this trigo system ?  ggauny@live.fr  09222017, 07:27 AM
RE: How solve this trigo system ?  Gerson W. Barbosa  09222017, 05:05 PM

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