换元,三角代换是什么
来源:学生作业帮 编辑:搜狗做题网作业帮 分类:数学作业 时间:2024/06/17 16:17:47
换元,三角代换是什么
![换元,三角代换是什么](/uploads/image/z/19496859-51-9.jpg?t=%E6%8D%A2%E5%85%83%2C%E4%B8%89%E8%A7%92%E4%BB%A3%E6%8D%A2%E6%98%AF%E4%BB%80%E4%B9%88)
sinx平方+cosx平方=1
1+tanx平方=secx平方
1+cotx平方=cosec平方
sin2x=2sinxcox
cos2x=cosx平方-sinx平方
=2cosx平方-1
=1-2sinx平方
tan2x=2tanx/(1-tanx平方)
sin(a+b)=sina * cosb + cosa * sinb
sin(a-b)=sina * cosb - cosa * sinb
cos(a+b)=coa * cosb - sina * sinb
cos(a-b)=coa * cosb + sina * sinb
tan(a+b)=(tana +tanb)/1-tana * tanb
tan(a-b)=(tana -tanb)/1+tana * tanb
sina +sinb= 2 sin (a+b)/2 * cos(a-b)/2
sina - sinb= 2 cos(a+b)/2 * sin(a-b)/2
cosa + cosb =2 cos(a+b)/2 * cos(a-b)/2
cosa - cosb =2 sin(a+b)/2 * sin(a-b)/2
sinacosb=【sin(a+b) + sin(a-b)】/2
cosasinb=【sin(a+b) - sin(a-b)】/2
cosacosb=【sin(a+b) + sin(a-b)】/2
sinasinb= -【sin(a+b) - sin(a-b)】/2
1+tanx平方=secx平方
1+cotx平方=cosec平方
sin2x=2sinxcox
cos2x=cosx平方-sinx平方
=2cosx平方-1
=1-2sinx平方
tan2x=2tanx/(1-tanx平方)
sin(a+b)=sina * cosb + cosa * sinb
sin(a-b)=sina * cosb - cosa * sinb
cos(a+b)=coa * cosb - sina * sinb
cos(a-b)=coa * cosb + sina * sinb
tan(a+b)=(tana +tanb)/1-tana * tanb
tan(a-b)=(tana -tanb)/1+tana * tanb
sina +sinb= 2 sin (a+b)/2 * cos(a-b)/2
sina - sinb= 2 cos(a+b)/2 * sin(a-b)/2
cosa + cosb =2 cos(a+b)/2 * cos(a-b)/2
cosa - cosb =2 sin(a+b)/2 * sin(a-b)/2
sinacosb=【sin(a+b) + sin(a-b)】/2
cosasinb=【sin(a+b) - sin(a-b)】/2
cosacosb=【sin(a+b) + sin(a-b)】/2
sinasinb= -【sin(a+b) - sin(a-b)】/2