y=tan2分之x-2分之x的倒数-搜答案-搜搜考试网

看图.

2x-y分之x+y=2,则2x-y=2(x+y)4x-2y分之x+y-4x+4y分之2x-y=2(2x-y)分之x+y-4(x+y)分之2x-y=4(x+y)分之x+y-4(x+y)分之2(x+y)=

（x的平方-y的平方)分之2xy+(x+y)分之x-(y-x)分之y=（x的平方-y的平方)分之2xy+(x+y)分之x+(x-y)分之y=(x²-y²)分之[2xy+x(x-y)

x+y分之4x-2y-2x-y分之4x+4y=2(2x-y)/(x+y)-4(x+y)/(2x-y)=2*2-4*(1/2)=4-2=2

2/3

3/4x=2/3y9x=8yx;y=8:9再问：你几年级呀？？？再答：呵呵，对的话你就采纳行了。再问：我还是不太明白●▽●再答：3/4x=2/3y9/4x=2y9x=8y再问：完全不懂o_O算了我写啦

（x分之x-y）-（y分之x+y）+（2xy分之x的平方-y的平方）=1-y/x-1-x/y+(x^2-y^2)/2xy=-2(y^2+x^2)/2xy+(x^2-y^2)/2xy=-(x^2+3y^

解原式=2(x-y)/(x+y)-(x+y)/3(x-y)=6(x-y)(x-y)/[3(x+y)(x-y)]-(x+y)x+y)/[3(x-y)(x+y)]=5(x-y)(x-y)/[(x+y)(x

因为X+2/X-Y=2所以X=2Y+2将X=2Y+2代入X+Y/3（X-Y）-（X-Y）/2（X+Y）=（3Y+2）/3（2Y+2-Y）-（2Y+2-Y）/2（3Y+2）接下来自己算

1/x+1/y=-2则(x-xy+y)/(x+xy+y)分子分母同除以xy=(1/x+1/y-1)/(1/x+1/y+1)=(-2-1)/(-2+1)=3

x+y=x-(x+3/2)^2+21/4=x-x^2-9/4-3x+21/4=-x^2-2x+12/4=-(x+1)^2+4因为-(x+1)^2

x+y分之x-y=2求x+y分之3x-3y减x-y分之2(x+y)的值x+y分之x-y=2x-y=2(x+y)(x+y)分之(3x-3y)-(x-y)分之2(x+y)的值x+y分之3x-3y=(x+y

x+y分之x-y=2x-y=2(x+y)求x+y分之3x-3y=(x+y)分之3(x-y)=(x+y)分之6(x-y)=6-x-y分之2(x+y)=-(x+y)分之2(x+y)=-2

角a终边在射线y=-3分之4x(x≤0）上a的终边在第2象限在a终边上取一点,横坐标x=-3,纵坐标y=4,|OP|=r=5∴sina=y/r=4/5,cosa=x/r=-3/5sin2a=2sina

(1)cosα=1/7,因为0＜α＜π/2,所以sinα=√(1-cosα)=√[1-(1/7)]=4√3/7所以tanα=sinα/cosα

由题可得（2x-y）/（3y）=y/x则：2x²-xy-3y²=0（2x-3y）（x+y）=0则2x-3y=0或者x+y=02x=3y或者x=-y所以：y分之x=3/2或者y分之x

(3x分之y)的平方×(-y分之x)的三次方÷(-x分之2y)方=(y²/9x²)(-x³/y³)(x²/4y²)=-x³/36y

tan2πx>=0kπ再问：不应该是(-1,-3/4)∪(-1/2,-1/4)？