|
|
|
GIÚP GẤP CHỨNG MINH CÁC ĐẲNG THỨC:l1 . $( \tan x + \cos x)x ^{2 } - ( \tan x - \cot x )x ^{2 } = 4 $2. $sin10 x^{o } . sinx50 ^{o } . sin 70x ^{o } = \frac {1 }{8}$
GIÚP GẤP CHỨNG MINH CÁC ĐẲNG THỨC:l Câu 1 : (tan x + cos x) 2
- (tan x – cot x)2 = 4
Câu 2: Sin10o.sin50o.sin70o = ⅛2 16.0pt;font-family:"Cambria Math","serif";mso-ascii-font-family:"Cambria Math";
mso-hansi-font-family:"Cambria Math";font-style:italic;mso-bidi-font-style:
normal'>tanNew Roman";
mso-bidi-theme-font:minor-bidi;mso-ansi-language:EN-US;mso-fareast-language:
EN-US;mso-bidi-language:AR-SA'>x-1 style="font-size:11.0pt;line-height:115%;font-family:"Calibri","sans-serif";
mso-ascii-theme-font:minor-latin;mso-fareast-font-family:Calibri;mso-fareast-theme-font:
minor-latin;mso-hansi-theme-font:minor-latin;mso-bidi-font-family:"Times New Roman";
mso-bidi-theme-font:minor-bidi;position:relative;top:9.0pt;mso-text-raise:-9.0pt;
mso-ansi-language:EN-US;mso-fareast-language:EN-US;mso-bidi-language:AR-SA"> o:spt="75" o:preferrelative="t"
path="m@4@5l@4@11@9@11@9@5xe" filled="f" stroked="f">
75pt;
height:24pt'>
src="file:///C:\DOCUME~1\adm_max\LOCALS~1\Temp\msohtmlclip1\01\clip_image001.png"
o:title="" chromakey="white"/>
+ 0pt;mso-ansi-font-size:16.0pt;mso-bidi-font-size:16.0pt;
font-family:"Cambria Math","serif";mso-ascii-font-family:"Cambria Math";
mso-fareast-font-family:"Times New Roman";mso-fareast-theme-font:minor-fareast;
mso-hansi-font-family:"Cambria Math";font-style:italic;mso-bidi-font-style:
normal'>cotx+1%;font-family:"Cambria Math","serif";
mso-fareast-font-family:"Times New Roman";mso-fareast-theme-font:minor-fareast;
mso-bidi-font-family:"Times New Roman";mso-bidi-theme-font:minor-bidi;
mso-ansi-language:EN-US;mso-fareast-language:EN-US;mso-bidi-language:
AR-SA'>cotpt;
line-height:115%;font-family:"Cambria Math","serif";mso-fareast-font-family:
"Times New Roman";mso-fareast-theme-font:minor-fareast;mso-bidi-font-family:
"Times New Roman";mso-bidi-theme-font:minor-bidi;mso-ansi-language:EN-US;
mso-fareast-language:EN-US;mso-bidi-language:AR-SA'>x-1 id="_x0000_i1025" type="#_x0000_t75" style='width:36pt;height:24pt'>
= -1
|