x^2+y^2=4.qiou 3x-4yde zhi
来源:百度知道 编辑:UC知道 时间:2024/09/24 00:26:24
dong le xieixe
设x=2sina,y=2cosa
3x-4y
=6sina+8cosa
=10sin(a+∮)
所以
-10<=3x-4y<=10
方法二;图象法,画x^2+y^2=4的图象 令3x-4y =Z变形为y=3/4x-z/4,因为x,y要满足x^2+y^2=4,所以直线与其相切(两次)即可求出 -10≤Z≤10,
但我个人感觉对于这道题来说wswss11986 - 魔法师 五级的解法要快一些
x^2+y^2=4.qiou 3x-4yde zhi
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3(x+y)-2(x-y)=9 5(x+y)+2(x-y)=-1
分解因式:x^2-y^2-x+y 5(x-y)^3+10(y-x)^2 x^2-6x-7 已知x^2+y^2-4x+6y+13=0,求x+y的直
(x-2y)^2+(x-y)(x-2y)-2(x-3y)(x-y)
1/4(x+y)+1/2(x+y)*(x+y)>=x*根号y+y*根号x
若3x-2y=0,求(x+y)/(x-y)+(x-y)/(x+y)的值
X-Y=3 2X+4Y=18 X=? Y=?
(x+y)/3=(x-y)/4 2x+3y=11