根号2倍sin(四分之派-x) 根号6(四分之派 x)化简
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√3/3sin(2x-π/2)=-√3/3cos2x∵x∈[-π/6,π/3]∴2x∈[-π/3,2π/3]∴当2x=2π/3时,cos2x取得最小值-1/2 -√3/3cos2
原式=1/2sinx+根号3/2cosx+sinx-根号3cosx+根号3/2cosx-3/2sinx(先全部展开)=0(最后合并同类项得0)
1f(x)=2sinX平方+2跟3sinxcosx+a把x=π/3代入f(x),sinπ/3=跟3/2cosπ/3=1/2f(x)=2*3/4+3/2+a=4a=1f(x)=跟3sin2x-cos2x
f(x)=(sinx)^2+2√3sin(x+π/4)cos(x-π/4)-(cosx)^2-√3=-((cosx)^2-(sinx)^2)+√3(sin(x+π/4+x-π/4)+sin(x+π/4
f(x)=sin2x+2sin(π/4-x)cos(π/4-x)=sin2x+cos2x=√2sin(2x+π/4)所以T=2π/2=πx属于[-π/12,π/2]得到2x+π/4属于[π/12,5π
f(x)=[2sin(x+π/3)+sinx]cosx-根号3sin^2x和差角公式展开f(x)=(sinx+根号3cosx+sinx)cosx-根号3sin2x=2sinx*cosx+根号3cosx
∫(-π/4,π/4)(x^3+cosx)/[1+sin^(2)x]dx=∫(-π/4,π/4)x^3/[1+sin^(2)x]dx+∫(-π/4,π/4)cosx/[1+sin^(2)x]dx(前者
y=sin(π/4—2X)=-sin(2x-π/4)的单调增区间即为sin(2x-π/4)的单调减区间,由π/2+2kπ≤2x-π/4≤3π/2+2kπ3π/4+2kπ≤2x≤7π/4+2kπ3π/8
如图手机提问的朋友在客户端右上角评价点【评价】,然后就可以选择【满意,问题已经完美解决】了
f'(x)=2√2cos(2x+π/4)当2nπ-π/2
f(x)=[1-√2sin(2x-π/4)]/cosx=[1-√2(sin2xcosπ/4-cos2xsinπ/4)]/cosx=[1-√2(√2/2*sin2x-√2/2*cos2x)]/cosx=
解cos(x+π/2)=-sinx=-√5/5利用诱导公式cos(π/2+x)=-sinx
cos45°+sin30°=√2/2+1/2=(√2+1)/2
1f(x)=2sinX平方+2跟3sinxcosx+a把x=π/3代入f(x),sinπ/3=跟3/2cosπ/3=1/2f(x)=2*3/4+3/2+a=4a=1f(x)=跟3sin2x-cos2x
y=根号2sin(2x-派)cos[2(x+派)]=根号2(-sin2x)cos2x=-根号2sin2xcos2x=-(根号2/2)sin4x是奇函数故最小正周期为2π/4=π/2,最小值=-√2/2
再答:再问:cosα的值取正还是负再答:不用管再答:没有用cos
原式=cos[2(π/4-a)]=cos(π/2-2a)=sin2a
题目的意思是-π/4再问:哦,对是五分之根号五再答:哦,这样子啊,好的,如果是(根号5)/5的话,下面解题:sin(π/4-a)=sinπ/4cosa-cosπ/4sina=(根号2)/2cosa-(