Geometry

[omicron]

1.Find the equation of the line joining A(-1, 9) to B(6, 12).
Another line passes through C(7, -5) and meets AB at right angles at D.
Find the equation of CD and calculate the coordinates of D.

Given That the coordinates of M are (K, -2K) and that the distance of AM is \sqrt{178}units, calculate the value of K.

How do i calculate the value of K?

2. Q is the reflection of the point(2,9) in the straight line y = 2x. Calculate the coordinates of Q.

[rhia]

1.Find the equation of the line joining A(-1, 9) to B(6, 12).
Another line passes through C(7, -5) and meets AB at right angles at D.
Find the equation of CD and calculate the coordinates of D.

Given That the coordinates of M are (K, -2K) and that the distance of AM is \sqrt{178}units, calculate the value of K.

How do i calculate the value of K?

|AM|^2=[(K+1)^2 + (-2K-9)^2] = 178 => K=2

2. Q is the reflection of the point(2,9) in the straight line y = 2x. Calculate the coordinates of Q.
If Q` is the reflection of Q about the line y=2x then the line y=2x is the perpendicular bisector of QQ`. QQ` has slope = -1/2 .Find the intersection pt.
which is the mid-pt of QQ`.

n:bugeye:b

[omicron]

Thanks....