1-cosx乘cos2x乘cos3x
@堵韦2641:(1 - cosxcos2xcos3x)/(1 - cosx)当x趋近于0时的极限 -
栾钓19647144523…… 由三角积化和差公式 cosxcos2xcos3x =(1/2)(cosx+cos3x)xos3x =(1/4)cos2x+(1/4)cos4x+1/4+(1/4)cos6x 原极限化为(x->0) (1-(1/4)cos2x-(1/4)cos4x-1/4-(1/4)cos6x)/(1-cosx) x->0 1-cosx~(1/2)x^2 上式=(1-(1/4)cos2x-(1/4)cos4x-1/4-(1/4...
@堵韦2641:高数limx - 0(1 - cosxcos2x)/(1 - cosx)求极限 -
栾钓19647144523…… 方法一 limx→0(1-cosxcos2x)/(1-cosx)=limx→0(1-cosxcos2x)'/(1-cosx)' (罗必塔法则0/0型,分子分母分别求导)=limx→0(sinxcos2x+2cosxsin2x)/sinx=limx→0(sinxcos2x+4cos^2xsinx)/sinx=limx→0(cos2x+4cos^2x)=1+4=5 方法二 limx→0(1-cosx(2...
@堵韦2641:已知函数f(x)=(1 - cos2x)乘以cosx的平方,求f(x)
栾钓19647144523…… f(x)=(1-cos2x)乘以cosx 的平方 =【1-(cos^2x-sin^2x)*cosx的平方 =[cos^2x+sin^2x-cos^2x+sin^2x]cos^2x =2sin^2xcos^2x =sin2x的平方/2
@堵韦2641:高数极限lim[1 - cosx(cos2x)^(1/2)]/x^2求解,快 - 作业帮
栾钓19647144523…… [答案] lim1-cosx(cos2x)^(1/2)/x^2=lim1-cosx(cos2x)^(1/2)*1+cosx(cos2x)^(1/2)/{x^21+cosx(cos2x)^(1/2)}=lim1-cosx^2cos2x/{x^21+cosx(cos2x)^(1/2)}=lim1-cosx^2(cosx^2-sinx^2)/{x^21+cosx(cos2x)^(1/2)}=limcosx^2+s...
@堵韦2641:[1 - (cosx)(cos2x)^1/2(cos3x)^1/3]/x^2的极限 - 作业帮
栾钓19647144523…… [答案] 答案:3 详细解答间图片,点击放大,再点击再放大.
@堵韦2641:1 - cos2x是怎么换算成2sin^22的 -
栾钓19647144523…… 1-cos(2x) =1-cos(x+x) =1-cosxcosx+sinxsinx =1-cos^2(x)+sin^2(x) =2sin^(x)
@堵韦2641:cosx乘cos2x乘cos4x乘cos8x的导数 -
栾钓19647144523…… 都乘以sinx 原式=sinx*cosx*cos2x*cos4x*cos8x/sinx =1/2sin2x*cos2x*cos4x*cos8x/sinx =1/4sin4x*cos4x*cos8x/sinx =1/8sin8x*cos8x/sinx =1/16 sin16x/sinx 后面就很简单了吧.
@堵韦2641:高数极限lim[1 - cosx(cos2x)^(1/2)]/x^2求解,在线等,快快 -
栾钓19647144523…… 解:lim1-cosx(cos2x)^(1/2)/x^2 =lim1-cosx(cos2x)^(1/2)*1+cosx(cos2x)^(1/2)/{x^21+cosx(cos2x)^(1/2)} =lim1-cosx^2cos2x/{x^21+cosx(cos2x)^(1/2)} =lim1-cosx^2(cosx^2-sinx^2)/{x^21+cosx(cos2x)^(1/2)} =limcosx^2+sinx^2+cosx^2sinx^2-cosx^4/{x^...
@堵韦2641:lim[(1 - cosx*cos2x****cosnx)/x^2]在x趋于0时 -
栾钓19647144523…… 原式=lim(1-cos2x)/x^2 =lim(2sin^x)/x^2 =2 如有疑问请追问 满意请采纳 如有其它问题请采纳此题后点求助, 答题不易,望合作O(∩_∩)O~
@堵韦2641:1 - cosx等于啥?
栾钓19647144523…… 2sin²(x/2)1-cosx等于 2sin²(x/2).由二倍角余弦公式cos2x=1-2sin²x,所以 cosx=1-2sin²(x/2),则1-cosx = 2sin²(x/2).倍角公式,是三角函数中非常实用的一类公式...
栾钓19647144523…… 由三角积化和差公式 cosxcos2xcos3x =(1/2)(cosx+cos3x)xos3x =(1/4)cos2x+(1/4)cos4x+1/4+(1/4)cos6x 原极限化为(x->0) (1-(1/4)cos2x-(1/4)cos4x-1/4-(1/4)cos6x)/(1-cosx) x->0 1-cosx~(1/2)x^2 上式=(1-(1/4)cos2x-(1/4)cos4x-1/4-(1/4...
@堵韦2641:高数limx - 0(1 - cosxcos2x)/(1 - cosx)求极限 -
栾钓19647144523…… 方法一 limx→0(1-cosxcos2x)/(1-cosx)=limx→0(1-cosxcos2x)'/(1-cosx)' (罗必塔法则0/0型,分子分母分别求导)=limx→0(sinxcos2x+2cosxsin2x)/sinx=limx→0(sinxcos2x+4cos^2xsinx)/sinx=limx→0(cos2x+4cos^2x)=1+4=5 方法二 limx→0(1-cosx(2...
@堵韦2641:已知函数f(x)=(1 - cos2x)乘以cosx的平方,求f(x)
栾钓19647144523…… f(x)=(1-cos2x)乘以cosx 的平方 =【1-(cos^2x-sin^2x)*cosx的平方 =[cos^2x+sin^2x-cos^2x+sin^2x]cos^2x =2sin^2xcos^2x =sin2x的平方/2
@堵韦2641:高数极限lim[1 - cosx(cos2x)^(1/2)]/x^2求解,快 - 作业帮
栾钓19647144523…… [答案] lim1-cosx(cos2x)^(1/2)/x^2=lim1-cosx(cos2x)^(1/2)*1+cosx(cos2x)^(1/2)/{x^21+cosx(cos2x)^(1/2)}=lim1-cosx^2cos2x/{x^21+cosx(cos2x)^(1/2)}=lim1-cosx^2(cosx^2-sinx^2)/{x^21+cosx(cos2x)^(1/2)}=limcosx^2+s...
@堵韦2641:[1 - (cosx)(cos2x)^1/2(cos3x)^1/3]/x^2的极限 - 作业帮
栾钓19647144523…… [答案] 答案:3 详细解答间图片,点击放大,再点击再放大.
@堵韦2641:1 - cos2x是怎么换算成2sin^22的 -
栾钓19647144523…… 1-cos(2x) =1-cos(x+x) =1-cosxcosx+sinxsinx =1-cos^2(x)+sin^2(x) =2sin^(x)
@堵韦2641:cosx乘cos2x乘cos4x乘cos8x的导数 -
栾钓19647144523…… 都乘以sinx 原式=sinx*cosx*cos2x*cos4x*cos8x/sinx =1/2sin2x*cos2x*cos4x*cos8x/sinx =1/4sin4x*cos4x*cos8x/sinx =1/8sin8x*cos8x/sinx =1/16 sin16x/sinx 后面就很简单了吧.
@堵韦2641:高数极限lim[1 - cosx(cos2x)^(1/2)]/x^2求解,在线等,快快 -
栾钓19647144523…… 解:lim1-cosx(cos2x)^(1/2)/x^2 =lim1-cosx(cos2x)^(1/2)*1+cosx(cos2x)^(1/2)/{x^21+cosx(cos2x)^(1/2)} =lim1-cosx^2cos2x/{x^21+cosx(cos2x)^(1/2)} =lim1-cosx^2(cosx^2-sinx^2)/{x^21+cosx(cos2x)^(1/2)} =limcosx^2+sinx^2+cosx^2sinx^2-cosx^4/{x^...
@堵韦2641:lim[(1 - cosx*cos2x****cosnx)/x^2]在x趋于0时 -
栾钓19647144523…… 原式=lim(1-cos2x)/x^2 =lim(2sin^x)/x^2 =2 如有疑问请追问 满意请采纳 如有其它问题请采纳此题后点求助, 答题不易,望合作O(∩_∩)O~
@堵韦2641:1 - cosx等于啥?
栾钓19647144523…… 2sin²(x/2)1-cosx等于 2sin²(x/2).由二倍角余弦公式cos2x=1-2sin²x,所以 cosx=1-2sin²(x/2),则1-cosx = 2sin²(x/2).倍角公式,是三角函数中非常实用的一类公式...