-
最佳答案:一、对二、cos(kπ-α)=-cosα不对,当k为偶数时,cos(kπ-α)=cos(2nπ-α)=cosα当k为奇数时,cos(kπ-α)=cos(2nπ+
-
最佳答案:sin(-16π/3)=-sin(16π/3)=-sin(4π+4π/3)=-sin(4π/3)=-sin(π+π/3)=sin(π/3)=根号3/2常用的诱导
-
最佳答案:cos(61π/12)=cos(π/12)=cos(π/3-π4)=(√2+√6)/4tan(35π/12)=tan(11π/12)=-tan(π/12)=-(
-
最佳答案:dy=e^sinx*cosxdx用到d(e^x)=e^xdx,d(sinx)=cosxdx
-
最佳答案:sin(-7/12)=sin(5π/12-π)=-sin(π-5π/12)=-sin5π/12=sin(3π/12+2π/12).=-sin(π/4+π/6)=
-
最佳答案:cos(-61π/12)=cos(6π-11π/12)=cos(-11π/12)=-cos15度=-cos(60-45)=-(cos60cos45+sin60s
-
最佳答案:类似吧.还有比如说x²+y²=1,则可以令x=sinα,y=cosα这类技巧.
-
最佳答案:(1)y’=sinx+cosx(2)f(x)'=2xe^x+x²e^x(3)f(x)=1-ln x/x²
-
最佳答案:sin(-7π/12)= -sin(7π/12)= -sin﹙π/3+π/4﹚= -(sinπ/3cosπ/4+cosπ/3sinπ/4)= -(√3/2 *