y=4x^2-5x+7/x-2(x>2),求y最值

来源：学生作业帮编辑：大师作文网作业帮分类：数学作业时间：2024/11/11 14:33:45

y = (4x^2-5x+7)/(x-2) = 4x+3+13/(x-2) = 4(x-2) +13/(x-2) +11,
因 x>2,得 y ≥ 2√[4(x-2) *13/(x-2)] +11 = 11+4√13,
等号在 4(x-2)=13/(x-2),即 x=2+√13/2 时取得.
即y的最小值是 y(2+√13/2) = 11+4√13

y=4x^2-5x+7/x-2(x>2),求y最值化简y=|6-x|-|2x+1|+|x+5|.然后求y的最值已知X.x+y.y-4x+2y+5=0,求4X.X-12X Y+9Y.y的值已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值? 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) 已知x,y是实数,且x^2+y^2-4x-6y+12=0,求：x/y的最值.（2）x^2+y^2的最值.（3）x-y的最已知x,y是实数,且x^2+y^2-4x-6y+12=0,求：x/y的最值.（2）x^2+y^2的最值.（3）x+y的最已知x=1/3,y=-1/2,求代数式x-(x+y)+(x+2y)-(x+3y)+(x+4y)-(x+5y)+...-( 已知x²+y²+5=2x+4y,求【2x²-(x-y)(x-y)】【(x+y-1)(x-y 1.已知:x-2y=3,求[(3x+2y)(3x-2y)-(x+2y)(5x-2y)]除4x 的值已知x-2y=2011,求[(3x+2y)(3x-2y)-(x+2y)(5x-2y)]÷4x的值. 若(x*x+y*y)(x*x+y*y)-4x*x*y*y=0,求代数式(x*x+5xy+y*y)/(x*x+2xy+y*