cos(a b)推导
![a2 b2-c2=2abcos c.](https://i.ecywang.com/upload/1/img1.baidu.com/it/u=2815617330,1871671703&fm=253&fmt=auto&app=138&f=JPEG?w=500&h=281)
a2 b2-c2=2abcos c.
图片尺寸1080x607![6,cos(a b)等于负0.6,且a,b为锐角,求cosb的值,解题思路](https://i.ecywang.com/upload/1/img0.baidu.com/it/u=181235252,3784568047&fm=253&fmt=auto&app=138&f=JPG?w=249&h=358)
6,cos(a b)等于负0.6,且a,b为锐角,求cosb的值,解题思路
图片尺寸249x358![根据cosa和cosb来求cos(a-b)的方法](https://i.ecywang.com/upload/1/img1.baidu.com/it/u=4251997015,2696976867&fm=253&fmt=auto&app=138&f=JPEG?w=470&h=205)
根据cosa和cosb来求cos(a-b)的方法
图片尺寸470x205![数学关于cosab](https://i.ecywang.com/upload/1/img0.baidu.com/it/u=2444838298,2683131793&fm=253&fmt=auto&app=138&f=JPEG?w=500&h=613)
数学关于cosab
图片尺寸2561x3139![数学:求证:锐角三角形中 (cosa cosb cosc)≤cos((a b c))](https://i.ecywang.com/upload/1/img0.baidu.com/it/u=46286958,2446852669&fm=253&fmt=auto&app=138&f=GIF?w=552&h=481)
数学:求证:锐角三角形中 (cosa cosb cosc)≤cos((a b c))
图片尺寸552x481![cosa=1/3,cos(a b)=-1/3,且a b属于(0,π/2),则cos(a-b)=?](https://i.ecywang.com/upload/1/img1.baidu.com/it/u=3633089087,3349593788&fm=253&fmt=auto&app=138&f=JPEG?w=887&h=500)
cosa=1/3,cos(a b)=-1/3,且a b属于(0,π/2),则cos(a-b)=?
图片尺寸1632x920![b2 c2- a2 c2-bc c- b 又 cosa= = = ,∴ cos2b= cosa a= 2b.](https://i.ecywang.com/upload/1/img1.baidu.com/it/u=1128528281,2057386257&fm=253&fmt=auto&app=138&f=JPEG?w=667&h=500)
b2 c2- a2 c2-bc c- b 又 cosa= = = ,∴ cos2b= cosa a= 2b.
图片尺寸1080x810![高中数学 诱导公式的推导asinα-bcosα=√(a05 b05)cos[α-arc](https://i.ecywang.com/upload/1/img1.baidu.com/it/u=2043121885,2835270734&fm=253&fmt=auto&app=138&f=PNG?w=500&h=241)
高中数学 诱导公式的推导asinα-bcosα=√(a05 b05)cos[α-arc
图片尺寸1040x501![若a b=120°,则函数y=cos^2a cos^2b的最大值是](https://i.ecywang.com/upload/1/img1.baidu.com/it/u=1738098409,3265577331&fm=253&fmt=auto&app=138&f=JPEG?w=259&h=369)
若a b=120°,则函数y=cos^2a cos^2b的最大值是
图片尺寸259x369![已知cos(a b)等于0,sinb等于三分之二,求sin(2a, 3b)](https://i.ecywang.com/upload/1/img2.baidu.com/it/u=1836738715,2440773673&fm=253&fmt=auto&app=138&f=JPEG?w=500&h=605)
已知cos(a b)等于0,sinb等于三分之二,求sin(2a, 3b)
图片尺寸569x689![cosa cosb = 2*cos(a b)/2 *cos(a-b)/2 sina sinb = 2*sin(a](https://i.ecywang.com/upload/1/img2.baidu.com/it/u=3590611615,3635068943&fm=253&fmt=auto&app=138&f=PNG?w=312&h=229)
cosa cosb = 2*cos(a b)/2 *cos(a-b)/2 sina sinb = 2*sin(a
图片尺寸312x229![求心形线r=a(1 cosθ)的全长,有图更好啦,心形线实在不大能理解,_百度](https://i.ecywang.com/upload/1/img2.baidu.com/it/u=3838949396,804556502&fm=253&fmt=auto&app=138&f=JPEG?w=450&h=800)
求心形线r=a(1 cosθ)的全长,有图更好啦,心形线实在不大能理解,_百度
图片尺寸450x800![4 两向量的夹角 0 a a cos , cos , cos a r r r i](https://i.ecywang.com/upload/1/img1.baidu.com/it/u=1167388886,3797123159&fm=253&fmt=auto&app=138&f=JPEG?w=667&h=500)
4 两向量的夹角 0 a a cos , cos , cos a r r r i
图片尺寸1080x810![1 锐角三角函数定义 正弦,余弦,正切,余切: a sin a , c b cos a](https://i.ecywang.com/upload/1/img2.baidu.com/it/u=3782255095,3472981990&fm=253&fmt=auto&app=138&f=JPEG?w=667&h=500)
1 锐角三角函数定义 正弦,余弦,正切,余切: a sin a , c b cos a
图片尺寸1080x810![在三角形abc,,角abc所对的边分别是abc,且cosa=4/5,求sin^2(b c)/2](https://i.ecywang.com/upload/1/img1.baidu.com/it/u=962288427,37342879&fm=253&fmt=auto&app=138&f=GIF?w=500&h=631)
在三角形abc,,角abc所对的边分别是abc,且cosa=4/5,求sin^2(b c)/2
图片尺寸1057x1333![cos(a-b)=cosacosb sinasinbc^2=a^2 b^2-2ab*cosccosc=(a^2 b](https://i.ecywang.com/upload/1/img1.baidu.com/it/u=169624886,367472863&fm=253&fmt=auto&app=138&f=JPEG?w=573&h=500)
cos(a-b)=cosacosb sinasinbc^2=a^2 b^2-2ab*cosccosc=(a^2 b
图片尺寸705x615![5 简单的三角恒等变换 第1课时 两角和与差的正弦,9,则sin 2,cos 22](https://i.ecywang.com/upload/1/img1.baidu.com/it/u=3264275190,3937942353&fm=253&fmt=auto&app=138&f=JPEG?w=500&h=708)
5 简单的三角恒等变换 第1课时 两角和与差的正弦,9,则sin 2,cos 22
图片尺寸800x1132![a2 cos a 2bc c2 b2 cos b 2ac a2 b2 c2 cosc](https://i.ecywang.com/upload/1/img0.baidu.com/it/u=3636809289,539846851&fm=253&fmt=auto&app=138&f=JPEG?w=667&h=500)
a2 cos a 2bc c2 b2 cos b 2ac a2 b2 c2 cosc
图片尺寸1080x810![锐角三角函数定义 正弦,余弦,正切,余切: b c a sin a , c b cos a](https://i.ecywang.com/upload/1/img1.baidu.com/it/u=1219291650,1400269663&fm=253&fmt=auto&app=138&f=JPEG?w=500&h=375)
锐角三角函数定义 正弦,余弦,正切,余切: b c a sin a , c b cos a
图片尺寸1080x810![基础稍差的学生使用 由此可得:余弦定理 a b c 2bc cos a 2 2 2](https://i.ecywang.com/upload/1/img1.baidu.com/it/u=3822507608,3831657048&fm=253&fmt=auto&app=138&f=JPEG?w=667&h=500)
基础稍差的学生使用 由此可得:余弦定理 a b c 2bc cos a 2 2 2
图片尺寸1080x810