(1/x²-cos²x/sin²x)
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证明:左边=[sin x−(1−cos x)](sin x+1−cos x)sin 2x=(2sin x2cosx2−2sin2
证明因为:tanx=sinx/cosx所以cosx=sinx/tanx(tanxsinx)/(tanx-sinx)分子分母同时除以tanx=sinx/(1-sinx/tanx)=sinx/(1-cos
symsxyeq=cos(x*y)*cos(x*(1-y))-0.5*x*sin(x*y)*sin(x*(1-y))-1;ezplot(eq)
这个方程无解取区间[-π,π]-1
(1+tanx)/(sinx+cosx)=(1+sinx/cosx)/(sinx+cosx)=(sinx+cosx)/cosx/(sinx+cosx)=1/cosx
Sinx-siny=2/3cosx-cosy=1/2分别平方得(Sinx-siny)^2=(2/3)^2(cosx-cosy)^2=(1/2)^2展开相加得-2cos(x-y)+2=4/9+1/4-2
题目应该是当x逼近到0得时候,limx^2*cos(1/x)=0lim(sin(x^2*cos(1/x)))/x=lim(x^2*cos(1/x))/x=lim(x*cos(1/x))=0再问:你用罗
左边=(1-2sinxcosx)/(cos²x-sin²x)=(sin²x+cos²x-2sinxcosx)/(cos²x-sin²x)=(
sin^4x-sin^2xcos^2x+cos^4x=sin^4x+2sin^2xcos^2x+cos^4x-3sin^2xcos^2x=(sin^2x+cos^2x)^2-3sin^2xcos^2x
3/2cosx-3/2(sinx)^2
2cosx(sinx-cosx)+1=2sinxcosx-2cosx^2+1=sin2x+1-2cosx^2=sin2x-cos2x=√2sin(2x-π/4)
你确定第一个符号是加号不是乘号?
(1)f(x)=2cos(x/2)·(sin(x/2)+cos(x/2))-1=2cos(x/2)·sin(x/2)+2cos^2(x/2)-1=sinx+cosx(倍角公式)=√2sin(x+π/4
该函数在x=0处的左右极限都没有比如x=1/(2npi+pi/2)时,f(x)=1x=1/(2npi-pi/2)时,f(x)=-1取n->无穷大所以在x=0处没有右极限,左极限同理
证明:∵cos²x-sin²x=cos2xcos⁴x+sin⁴x=1-2cos²xsin²x=1-(1-cos4x)/4=3/4+(co
f(x)=2cosx*sinx-2cosx^2+1f(x)=sin2x-cos2xf(x)=根号2*sin(2x-45)周期T=π
(x*sinx*cosx)'=(1/2xsin2x)'=1/2(sin2x+xcos2x*2)=1/2sin2x+xcos2x
可用凑微分法如图积分.经济数学团队帮你解答,请及时采纳.
2(√3/2sinx+1/2cosx)=2sin(x+π/6)√2*√2(√2/2sinx-√2/2cosx)=2sin(x-π/4)(3)解;2√2(1/2cosx-√3/2sinx)=2√2cos
sin^4x-sin^2xcos^2x+cos^4x=sin^4x+2sin^2xcos^2x+cos^4x-3sin^2xcos^2x=(sin^2x+cos^2x)^2-3sin^2xcos^2x