find max. value of f(x) = 3sin3x + 4cos4x
how to solve this problem
所有跟帖:
• x=-90, f(x)=3+4=7 -yddad- ♂ (0 bytes) () 03/09/2015 postreply 17:49:30
• not right by looking at the graph. -酷胖- ♀ (185 bytes) () 03/09/2015 postreply 17:54:15
• sin(-270)=1, cos (-360)=1 ? -yddad- ♂ (0 bytes) () 03/09/2015 postreply 18:00:29
• 对,Max value=7. Min value is 3sin(-135)+4cos(-180)>-7, so -nyagela- ♀ (0 bytes) () 03/09/2015 postreply 20:28:30
• so Max value+Min value>0 -nyagela- ♀ (0 bytes) () 03/09/2015 postreply 20:29:20
• when x = 3*pi/2 (or 270 degree) f(x) = 7 = max -河舟- ♂ (0 bytes) () 03/09/2015 postreply 22:48:11