Tassader-VIII ¼g¨ì:§Ú¹ï²Ä¤@ÃD¦³ÂIºÃ°ÝC.......
sin4X+sin2X=sin3X+sinX
2*sin3X*cosX=2sin2X*cosX
sin3X*cosX-sin2X*cosX=0
cosX(sin3X-sin2X)=2*cosX*cos((5/2)*X)*sin(X/2)=0
©Ò¥H cosX=0 or cos((5/2)*X)=0 or sin(X/2)=0
·ícosX=0 X=pi/2 or (3/2)*pi
·ícos((5/2)*X)=0 (5/2)*X=pi/2 or (3/2)*pi
X=pi/5 or (3/5)*pi
·ísin(X/2)=0 X/2=0 or pi X=0 or 2pi
But 0<=X<2pi
©Ò¥H¥u¦³5Ó¸Ñ
³Ì·í¸Ñ¬O(3/2)*pi
³o¼Ë¦³¿ù¶Ü