sinx+1-cosx

解鸦虹2464求证!sinx/(1+cosx)=(1 - cosx)/sinx -
王堂柴18012131575 ______[答案] 证明: 左=sinx/(1+cosx) =sinx(1-cosx)/[(1+cosx)(1-cosx)] =sinx*(1-cosx)/(1-cos²x) =sinx(1-cosx)/sin²x =(1-cosx)/sinx =右 ∴ 等式成立

解鸦虹2464sinx/(1 - cosx) 求导 -
王堂柴18012131575 ______ y=1/[(1-cosx)/sinx] =1/tan(x/2) =cot(x/2) 所以 y'=-csc²(x/2)*(x/2)' =-csc²(x/2)/2

解鸦虹24641 - cosx 为什么等于 1 - cosx =2sin²(x/2) 1 - cosx =1 - [1 - 2sin²(x/2)] =2sin²(x/2) 另外 sinx+cosx=1 是1 - cosx 为什么等于2sin²(x/2) -
王堂柴18012131575 ______[答案] 二倍角余弦公式 cos2x=1-2sin^2x 所以 cosx=1-2sin^2(x/2) 所以 1-cosx = 2sin²(x/2) sinx+cosx=1 不对 是这个 sin^2x+cos^2x=1

解鸦虹2464求证!sinx/(1+cosx)=(1 - cosx)/sinx -
王堂柴18012131575 ______ 证明: 左=sinx/(1+cosx) =sinx(1-cosx)/[(1+cosx)(1-cosx)] =sinx*(1-cosx)/(1-cos²x) =sinx(1-cosx)/sin²x =(1-cosx)/sinx =右 ∴ 等式成立

解鸦虹24641+sinx - cosx/1+sinx+cosx=2 求tanx
王堂柴18012131575 ______ 1+sinx-cosx =sinx+(1-cosx) =2sin(x/2)cos(x/2)+2sin(x/2)^2 =2sin(x/2)[sin(x/2)+cos(x/2)] 1+sinx+cosx =sinx+(1+cosx) =2sin(x/2)cos(x/2)+2cos(x/2)^2 =2cos(x/2)[sin(x/2)+cos(x/2)] 所以原等式可化为 tan(x/2)=2 所以 tanx =2tan(x/2)/(1-tan(x/2)^2) =2*2/(1-2^2) =-4/3

解鸦虹2464高数 1 / sinx+cosx 定积分 -
王堂柴18012131575 ______[答案] ∫ 1/(sinx + cosx) dx = ∫ 1/[√2sin(x + π/4)] dx = (1/√2)∫ csc(x + π/4) d(x + π/4) = (1/√2)ln|csc(x + π/4) - cot(x + π/4)| + C

解鸦虹2464求limx→0 (e^x - 1)sinx/1 - cosx -
王堂柴18012131575 ______[答案] limx→0 (e^x-1)sinx/1-cosx =limx→0[ (e^x))sinx+ (e^x-1)cosx]/sinx =limx->0e^x+limx-0(e^x-1)cosx]/sinx =1+limx->0[(e^x)cosx]-(e^x-1)sinx]/cosx =1+1-0 =2

解鸦虹2464求证:[(sinx+cosx - 1)(sinx - cosx+1)]/sin2x=(1 - cosx)/sinx -
王堂柴18012131575 ______ [(sinx+cosx-1)(sinx-cosx+1)]/sin2x =[sinx+(cosx-1)][sinx-(cosx-1)]/sin2x =[(sinx)^2-(cosx-1)^2]/sin2x =[(sinx)^2-(cosx)^2+2cosx-1]/sin2x =[(sinx)^2-(cosx)^2+2cosx-1]/sin2x =-[-(sinx)^2+(cosx)^2-2cosx+1]/sin2x =-[1-(sinx)^2+(cosx)^2-2cosx]/sin2x =-[(...

解鸦虹2464已知 1+cosx=3sinx ,求 sinx - cosx -
王堂柴18012131575 ______[答案] 已知公式:sinx*sinx+cosx*cosx=1 (1); 由原式知cosx=3sinx-1,两边平方得:cosx*cosx=9sinx*sinx-6sinx+1,代入(1)中,得10sinx*sinx=6sinx.解出sinx=0或3/5;对应的,cosx=-1或4/5.所以sinx-cosx=1或-1/5.

解鸦虹2464怎么证明1 - cosx/sinx=sinx/1+cosx怎么证明? -
王堂柴18012131575 ______[答案] 因为 sin²x+cos²x=1 所以 sin²x=1-cos²x=(1-cosx)(1+cosx) 所以 sinx/(1+cosx)=(1-cosx)/sinx 祝开心