Question #dccca

2 Answers
Jan 22, 2018

See a solution process below:

Explanation:

The slope of a line can be found by using the formula: #m = (color(red)(y_2) - color(blue)(y_1))/(color(red)(x_2) - color(blue)(x_1))#

Where #m# is the slope and (#color(blue)(x_1, y_1)#) and (#color(red)(x_2, y_2)#) are the two points on the line.

The slope of the line passing through #(-3, 4)# and #(1, 2)# is:

#m_1 = (color(red)(2) - color(blue)(4))/(color(red)(1) - color(blue)(-3)) = (color(red)(2) - color(blue)(4))/(color(red)(1) + color(blue)(3)) = -2/4 = -1/2#

The slope of the line passing through #(-1, 3)# and #(1, 1)# is:

#m_2 = (color(red)(1) - color(blue)(3))/(color(red)(1) - color(blue)(-1)) = (color(red)(1) - color(blue)(3))/(color(red)(1) + color(blue)(1)) = -2/2 = -1#

Given a line with slope #m#, a line perpendicular to this line, let's call it #m_p# will have a slope the negative inverse of the original line. Or:

#m_p = -1/m#

The line perpendicular to the first line therefore would have a slope:

#m_(p1) = (-1)/(-1/2) = 2#

This is not the slope of the second line therefore these two lines are not perpendicular.

Jan 22, 2018

Using slope

Explanation:

Slope #m=(y2-y1)/(x2-x1)#
And for 2 lines to be perpendicular the product of their slopes must be = -1
Therefore on finding the slopes we get
#m1=(2-4)/(1-(-3)) = -1/2#
#m2=(1-3)/(1-(-1)) = -2/2 = -1#
But #m1*m2 != -1#
Hence they are not perpendicular
Hope u find it helpful :)