ÌâÄ¿ÄÚÈÝ

£¨2012•ÃàÑôÈýÄ££©ÒÑÖªº¯Êýf£¨x£©=Asin£¨wx+¦Õ£©£¨A£¾0£¬w£¾0£¬|¦Õ|£¼
¦Ð
2
£¬x¡ÊR£©ÔÚÒ»¸öÖÜÆÚÄÚµÄͼÏóÈçͼËùʾ£®Ôòy=f£¨x£©µÄͼÏó¿ÉÓɺ¯Êýy=cosxµÄͼÏó£¨×Ý×ø±ê²»±ä£©£¨¡¡¡¡£©
·ÖÎö£ºÓɺ¯Êýf£¨x£©=Asin£¨wx+¦Õ£©£¨A£¾0£¬w£¾0£¬|¦Õ|£¼
¦Ð
2
£¬x¡ÊR£©ÔÚÒ»¸öÖÜÆÚÄÚµÄͼÏó¿ÉµÃ A=1£¬Çó³ö w=2£¬¦Õ=
¦Ð
3
£¬¿ÉµÃº¯Êýf£¨x£©=sin£¨2x+
¦Ð
3
£©£®ÔÙÓɺ¯Êýy=Asin£¨¦Øx+∅£©µÄͼÏó±ä»»¹æÂÉ£¬µÃ³ö½áÂÛ£®
½â´ð£º½â£ºÓɺ¯Êýf£¨x£©=Asin£¨wx+¦Õ£©£¨A£¾0£¬w£¾0£¬|¦Õ|£¼
¦Ð
2
£¬x¡ÊR£©ÔÚÒ»¸öÖÜÆÚÄÚµÄͼÏó¿ÉµÃ A=1£¬
1
4
T
=
1
4
2¦Ð
w
=
¦Ð
12
+
¦Ð
6
£¬½âµÃ w=2£®
Ôٰѵ㣨
¦Ð
12
£¬1£©´úÈ뺯ÊýµÄ½âÎöʽ¿ÉµÃ 1=sin£¨2¡Á
¦Ð
12
+¦Õ£©£¬¼´ sin£¨
¦Ð
6
+¦Õ£©=1£®
ÔÙÓÉ|¦Õ|£¼
¦Ð
2
£¬¿ÉµÃ ¦Õ=
¦Ð
3
£¬¹Êº¯Êýf£¨x£©=sin£¨2x+
¦Ð
3
£©£®
°Ñº¯Êýy=cosxµÄͼÏóÏȰѸ÷µãµÄºá×ø±êËõ¶Ìµ½Ô­À´µÄ
1
2
±¶£¬¿ÉµÃy=cos2xµÄͼÏó£¬ÔÙÏòÓÒƽÒÆ
¦Ð
12
¸öµ¥Î»¿ÉµÃ
y=cos2£¨x-
¦Ð
12
£©=cos£¨2x-
¦Ð
6
£©=sin[
¦Ð
2
-£¨2x-
¦Ð
6
£©]=sin£¨
2¦Ð
3
-2x£©=sin[¦Ð-£¨
2¦Ð
3
-2x£©]=sin£¨2x+
¦Ð
3
£©=f£¨x£©µÄͼÏó£®
¹ÊÑ¡B£®
µãÆÀ£º±¾ÌâÖ÷Òª¿¼²éÓÉy=Asin£¨¦Øx+∅£©µÄ²¿·ÖͼÏóÇó½âÎöʽ£¬º¯Êýy=Asin£¨¦Øx+∅£©µÄͼÏó±ä»»¹æÂÉ£¬ÊôÓÚÖеµÌ⣮
Á·Ï°²áϵÁдð°¸
Ïà¹ØÌâÄ¿

Î¥·¨ºÍ²»Á¼ÐÅÏ¢¾Ù±¨µç»°£º027-86699610 ¾Ù±¨ÓÊÏ䣺58377363@163.com

¾«Ó¢¼Ò½ÌÍø