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Aim: Review the distance and midpoint. Do Now: in the triangle, find the lengths of two legs. (3,6). (-2,4). (3,4). Distance between a point and a line. y = x + 2. l. (2,1). P.
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Aim: Review the distance and midpoint Do Now: in the triangle, find the lengths of two legs (3,6) (-2,4) (3,4)
Distance between a point and a line y = x + 2 l (2,1) P We first need to draw a perpendicular segment from P to the line and intersect a point QP and Q
The slope of line l is 1 then the slope of PQ must be -1, since they are perpendicular to each other Use point-slope form of a line to get y – 1= -1(x – 2) y – 1 = -x + 2, y = -x + 3 Solve the system of equations y = x + 2 y = -x + 3
= Distance from a point to a line Ax + By + C = 0 We can use this formula to check our answer by rewriting y = x + 2 into x – y + 2 = 0 A = 1, B = –1 and C = 2
= = Midpoint formula:
Drill Find the distance from the point (1,2) to line x + 2y = 3 2. Find the distance from the point (-3,4) to line 2x– y = – 4 3. Points (-1,6) and (3,-5) are the endpoints of the diameter of a circle, find the coordinates of the center