cos150 µÈÓÚ
cos150¡ã=( ) A. 3 2 B. - 3 2 C. 1 2 D. - 1 2
cos150¡ã=cos(180¡ã-30¡ã)=-cos30¡ã=- 3 2 ,¹ÊÑ¡B.
cos 150¶ÈµÈÓÚ¶àÉÙ?
¸ù¾ÝÒÔÉϹ«Ê½µÃ³ö´ð°¸cos150=cos(180-30)=-cos30=-¡Ì3/2¡£
cos150¡ãµÈÓÚ¶àÉÙ,ÔÚͼÖбê×¢
ÒòΪ ¹«Ê½Cos(90¡ã+a)= £Sin a¡£ËùÒÔ Cos150¡ã =Cos(90¡ã+60¡ã)= £Sin60¡ã = £(3^(1/2))/2 Ò²¾ÍÊÇÎÒÃÇËù˵µÄ£¬¸º¶þ·ÖÖ®¸ùºÅÈý¡£
cos150¶ÈÔõôÇó?
cos150=¡ªcos30 cosx=¡ªcos£¨Ø£¡ªx£©
COS150¶ÈµÈÓÚ¶àÉÙ?Òª¹ý³Ì?SIN150¶ÈÊǶàÉÙ?Ò²Òª¹ý³Ì? - °Ù¶È...
COS150¶È=-COS30¶È=-(3^0.5)/2 SIN150¶È=SIN30¶È=0.5
cos150¡ãµÄÖµµÈÓÚ( ) A. B. C. D.
ÀûÓÃÓÕµ¼¹«Ê½cos£¨180¡ã-¦Á£©=-cos¦Á»¯¼òºó£¬ÔÙ¸ù¾ÝÌØÊâ½ÇµÄÈý½Çº¯ÊýÖµ¼´¿ÉÇó³öÖµ£® ¡¾½âÎö¡¿ cos150¡ã =cos£¨180¡ã-30¡ã£© =-cos30¡ã =- £® ¹ÊÑ¡D...
Ö±½ÇÈý½ÇÐÎÕýÏÒcosµÄ0¶ÈÖµ30¶ÈÖµ60¶ÈÖµ90¶ÈÖµ120¶ÈÖµ...
cos0=1 cos30=2·ÖÖ®¸ù3 cos60=1/2 cos90= 0 cos120=-1/2 cos150=-2·ÖÖ®¸ù3 cos180=-1
cos( - a)=cos aΪʲô?ÊÇcos - 150µÈÓÚcos30?
cos(-a)=cos a=x/r -aÔÚµÚËÄÏóÏÞ½Ç aÔÚµÚÒ»ÏóÏÞ½Ç x¶¼ÊÇÕýµÄ,ËùÒÔËüÃÇÏàµÈ¡£ cos-150=cos150=cos(180-30)=-cos30 ½âÎö¿´²»¶®?Ãâ·Ñ²é¿´Í¬ÀàÌâÊÓÆµ½âÎö²é¿´½â´ð ...
cos150¶ÈÔõôËã
cos150=cos(90+60)=cos90*cos60-sin90*sin60=0-¸ùºÅ3/2=-¸ùºÅ3/2¡£sinºÍcosÊÇÕýÏÒºÍÓàÏҵķûºÅ¡£ÕýÏÒµÄÊýѧº¬ÒâÊÇÔÚÖ±½ÇÈý½ÇÐÎÖУ¬Ä³½ÇµÄÕýÏÒÖµµÈÓڸýǶÔÓ¦µÄ...
sinºÍcos¸÷½ÇµÄÖµ ¶¼ÒªÊ®¶þ¸ö½Ç¶ÈµÄ·Ö±ðÒª30¡ã 60¡ã...
½Ç¶Èsin cos30 0.5 ¡Ì3/260 ¡Ì3/2 0.590 1 0120 ¡Ì3/2 -0.5150 0.5 -¡Ì3/2180 0 -1210 -0.5 -¡Ì3/2240 -¡Ì3/2 -0.5270 -1 0300 -¡Ì3/2 0.5330 -0.5 ¡Ì...