sin^2Xsin^2B+cos^2Xcos^2B-1/2cos2Xcos2B快

sin^2Xsin^2B+cos^2Xcos^2B-1/2cos2Xcos2B快 化简sin^2x+sin^2y-sin^2xsin^2y+cos^2xcos^2y 化简sin^2Xsin^2Y+cos^2Xcos^2Y-0.5cos2Xcos2Y ∫(cos√x)dx答案2√xsin√x-2sin√x+c ∫cos2x/(cos^2xsin^2x) 不定积分cos2x/cos^2xsin^2xdx 求不定积分cos^3Xsin^2Xdx 求证 cos*xcos*y + sin*xsin*y + sin*xcos*y + xin*ycos*x = 1cos*xcos*y + sin*xsin*y + sin*xcos*y + sin*ycos*x = 1注意：[*] 的意思是 [ ^2 ]写下左右过程.. cos xsin b-sin xcos b和sin xcos x- 求积分 cos2x/cos^xsin^2x dx求积分cos2x/cos^xsin^2x dx (x^2cos^2x-sin^2x)/x^2cos^2xsin^2x （x->0）lim (x^2cos^2x-sin^2x)/x^2cos^2xsin^2x （x->0）=lim [cos^2x-(sin^2x/x^2)]/cos^2xsin^2x=lim (cos^2x-1)/sin^2x=lim -sin^2x/sin^2x=-1这样解错在哪啊?小弟感激不尽 化简cos(a-兀)/sin(兀-a) xsin(a-2兀)Xcos(2兀-a)要详细过程! 化简cos(x-兀)/sin(兀-x) xsin(x-2兀)Xcos(2兀-x)求过程! 请问cos2x/(cos^2xsin^2x)怎么算? ∫cos^4xsin^2xdx怎么积分? 关于sin^2x+cos^2x 的应用式子：cos^6x+sin^6x=（cos^2x+sin^2x)(cos^4x-cos^2xsin^x+sin^4x)=(cos^2x+sin^2x)^2-3sin^2xcos^2x 求这两步算法中的具体思路 ps:cos^2x=cosx的二次方 三角函数 同角三角函数关系式 sin²x-sinxcosx+cos²xsin²x-sinxcosx+cos²x tan=2求值的详细步奏 2sin的平方xsin^2(π/8)-cos^2(π/8) 我知道是2sin^2-1 但是不知道怎么计算啊..