ρcos4分之π等于多少？ sin四分之π和cos四分之π分别等于多少
cos\u56db\u5206\u4e4b\u03c0\u7b49\u4e8e\u591a\u5c11(\u68392)/2 \u4e0d\u7528\u8c22\uff0c\u671b\u91c7\u7eb3
sin\u56db\u5206\u4e4b\u03c0=sin45\u5ea6=2\u5206\u4e4b\u6839\u53f72\u3002
cos\u56db\u5206\u4e4b\u03c0=Cos45\u5ea6=2\u5206\u4e4b\u6839\u53f72\u3002
\u7279\u6b8a\u89d2\u7684\u4e09\u89d2\u51fd\u6570\u503c\uff1a
\uff081\uff09sin
0\u00b0
=
0\u3002cos
0\u00b0
=
1\u3001tan
0\u00b0
=
0\u3002
\uff082\uff09sin
30\u00b0
=
1/2\u3001cos
30\u00b0
=
\u221a3/2\u3001tan
30\u00b0
=
\u221a3/3\u3002
\uff083\uff09sin
45\u00b0
=
\u221a2/2\u3001cos
45\u00b0
=
\u221a2/2\u3001tan
45\u00b0
=
1\u3002
\uff084\uff09sin
60\u00b0
=
\u221a3/2\u3001cos
60\u00b0
=
1/2\u3001tan
60\u00b0
=
\u221a3\u3002
\uff085\uff09sin
90\u00b0
=
1\u3001cos
90\u00b0
=
0\u3002
\u6269\u5c55\u8d44\u6599
\u4e8c\u500d\u89d2\u516c\u5f0f
sin2\u03b1=2sin\u03b1cos\u03b1
tan2\u03b1=2tan\u03b1/(1-tan^2(\u03b1))
cos2\u03b1=cos^2(\u03b1)-sin^2(\u03b1)=2cos^2(\u03b1)-1=1-2sin^2(\u03b1)
\u534a\u89d2\u516c\u5f0f
sin^2(\u03b1/2)=(1-cos\u03b1)/2
cos^2(\u03b1/2)=(1+cos\u03b1)/2
tan^2(\u03b1/2)=(1-cos\u03b1)/(1+cos\u03b1)
tan(\u03b1/2)=sin\u03b1/(1+cos\u03b1)=(1-cos\u03b1)/sin\u03b1
=ρ×√2/2
绛旓細2鍒嗕箣鏍瑰彿2銆傚洜涓蟺鍦ㄤ笁瑙掑嚱鏁扮殑璁＄畻涓槸180搴︼紝鎵浠cos4鍒嗕箣涓蟺灏鏄cos45搴︼紝鏍规嵁涓夎鍑芥暟鐨勫叕寮廲os45搴﹀氨绛変簬2鍒嗕箣鏍瑰彿2銆
绛旓細鎵浠4/蟺绛変簬鐩磋鐨勪簩鍒嗕箣涓锛屽氨鏄90掳梅2=45掳銆傚湪鍏蜂綋璁＄畻涓紝瑙掑害浠ュ姬搴︾粰鍑烘椂锛岄氬父涓嶅啓寮у害鍗曚綅锛岀洿鎺ュ啓鍊笺傛渶鍏稿瀷鐨勪緥瀛愭槸涓夎鍑芥暟锛屽sin 8蟺銆乼an (3蟺锛2)銆傚埄鐢ㄥ姬搴︾殑璇濓紝鍒檒=|伪锝渞锛屽嵆伪鐨勫ぇ灏忎笌鍗婂緞涔嬬Н銆傜壒娈婅鐨勪笁瑙掑嚱鏁板硷細锛1锛塻in 0掳 = 0銆cos 0掳 = 1銆乼an 0...
绛旓細绛旀锛1 cos4蟺 =cos4*180 =cos2*360 =cos0 =1 sin4蟺=sin4*180=sin2*360=sin0=0
绛旓細cos3鍒嗕箣娲=1/2 sin3鍒嗕箣蟺绛変簬鈭3/2
绛旓細cos璐4鍒嗗瓙蟺=cos4鍒嗗瓙蟺=鏍瑰彿2/2
绛旓細cos鐨勫洓娆℃柟8鍒嗕箣蟺-sin鐨勫洓娆℃柟8鍒嗕箣蟺绛変簬銆奵os鐨勪簩娆℃柟8鍒嗕箣蟺+sin鐨勪簩娆℃柟8鍒嗕箣蟺銆嬩箻浠ャ奵os鐨勪簩娆℃柟8鍒嗕箣蟺+sin鐨勪簩娆℃柟8鍒嗕箣蟺銆嬬瓑浜 1涔樹互銆奵os鐨勪簩娆℃柟8鍒嗕箣蟺-sin鐨勪簩娆℃柟8鍒嗕箣蟺銆嬬瓑浜 cos鐨4鍒嗕箣蟺绛変簬 2鍒嗕箣鏍瑰彿2 ...
绛旓細褰撶劧鐩存帴浠ｅ叆鍗冲彲 cos蟺/4=鈭2/2 閭ｆ牴鍙(cos蟺/4)=鈭(鈭2/2)=2^(-1/4)浣跨敤璁＄畻鍣ㄥ緱鍒 绾绛変簬0.841
绛旓細cos浜鍒嗕箣蟺绛変簬0銆備綑寮︼紙浣欏鸡鍑芥暟锛夛紝涓夎鍑芥暟鐨勪竴绉嶃傚湪Rt鈻矨BC锛堢洿瑙掍笁瑙掑舰锛変腑锛屸垹A鐨勪綑寮︽槸瀹冪殑閭昏竟姣斾笁瑙掑舰鐨勬枩杈癸紝鍗砪osA=b/c锛屼篃鍙啓涓篶osa=AC/AB銆備綑寮﹀嚱鏁帮細f(x)=cosx锛坸鈭圧锛夈傛牴鎹笁瑙掑嚱鏁扮殑瀹氫箟锛歝osa=x/r (x琛ㄧず瑙抋缁堣竟涓婁竴鐐圭殑妯潗鏍囷紝r琛ㄧず杩欑偣鍒板師鐐圭殑璺濈)銆傚洜涓猴紝褰...
绛旓細cos浜鍒嗕箣蟺绛変簬澶氬皯cos浜屽垎涔嬒绛変簬0銆備綑寮,涓夎鍑芥暟鐨勪竴绉嶃傚湪Rt鈻矨BC涓,鈭燗鐨勪綑寮︽槸瀹冪殑閭昏竟姣斾笁瑙掑舰鐨勬枩杈,鍗砪osA=b/c,涔熷彲鍐欎负cosa=AC/AB銆備綑寮﹀嚱鏁:f=cosx銆傛牴鎹笁瑙掑嚱鏁扮殑瀹氫箟:cosa=x/r銆傚洜涓,褰揳=蟺/2鏃,杩欑偣鐨勬í鍧愭爣x=0,杩欑偣鍒板師鐐圭殑璺濈r涓嶇瓑浜0銆傛墍浠,cos=x/r=0/r=0銆2蟺琛ㄧず36...
绛旓細鏍瑰彿2/2
