A perpendicular bisector, CD is drawn through point C on AB. 

If the coordinates of point A are (-3, 2) and the coordinates of point B are (7, 6), the x-intercept of CD is[ A(3,0) B(18/5,0) C(9,0) D(45/2,0) ] . Point [ A(-52,117) B(-20,57) C(32,-71) D(-54,-128) ] lies on CD.

Respuesta :

Answer:

The x-intercept of CD is B(18/5,0). The point C(32,-71) lies on the line CD.

Step-by-step explanation:

Given information: CD is perpendicular bisector of AB.

The coordinates of point A are (-3, 2) and the coordinates of point B are (7, 6).

Midpoint of AB is C.

[tex]C=(\frac{x_1+x_2}{2},\frac{y_1+y_2}{2})=(\frac{7-3}{2},\frac{2+6}{2})=(2,4)[/tex]

The coordinates of C are (2,4).

The slope of line AB is

[tex]m_1=\frac{y_2-y_1}{x_2-x_1}=\frac{6-2}{7-(-3)}=\frac{4}{10}=\frac{2}{5}[/tex]

The product of slopes of two perpendicular lines is -1. Since the line CD is perpendicular to AB, therefore the slope of CD is

[tex]m_2=-\frac{5}{2}[/tex]

The point slope form of a line is

[tex]y-y_1=m(x-x_1)[/tex]

The slope of line CD is [tex]-\frac{5}{2}[/tex] and the line passing through the point (2,4), the equation of line CD is

[tex]y-4=-\frac{5}{2}(x-2)[/tex]

[tex]y=-\frac{5}{2}x+5+4[/tex]

[tex]y=-\frac{5}{2}x+9[/tex]       .... (1)

The equation of CD is [tex]y=-\frac{5}{2}x+9[/tex].

Put y=0, to find the x-intercept.

[tex]0=-\frac{5}{2}x+9[/tex]

[tex]\frac{5}{2}x=9[/tex]

[tex]x=\frac{18}{5}[/tex]

Therefore the x-intercept of CD is B(18/5,0).

Put x=-52 in equation (1).

[tex]y=-\frac{5}{2}(-52)+9=139[/tex]

Put x=-20 in equation (1).

[tex]y=-\frac{5}{2}(-20)+9=59[/tex]

Put x=32 in equation (1).

[tex]y=-\frac{5}{2}(32)+9=-71[/tex]

Put x=-54 in equation (1).

[tex]y=-\frac{5}{2}(-54)+9=144[/tex]

Only point (32,-71) satisfies the equation of CD. Therefore the point C(32,-71) lies on the line CD.

Answer:

The x-intercept of CD is B(18/5,0). The point C(32,-71) lies on the line CD.

Step-by-step explanation:

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