请教数学paper 1

f(x)=x^3-7x^2+17x-11
因为range这 x^2 +17 ≤ 7x + (11/x)给了"暗示”
其实这问题解了在别的论坛

哦。。　好的　

又有疑问了...拍谢!

1. Write the equation of the line with gradient m and passes the point P(0,18). Show that this line is the tangent to the circle with centre C(4,6) and the radius 10 units with m satisfies the equation 21m^2 -24m -11 = 0.

2. A point moves such that its distance from the point A(-2,3) is twice its distance from the point B(1,-1). Show that the locus of this point is a circle and state its centre and radius.

第一题不懂他的show是什么意思..
第二题的又怎样叫show?!

1. What is the condition for a line being tangent to a circle? If you know the condition well, that you can "show" it.

2. You must know the equation of a circle.