Find the equations of the straight lines drawn through the point #(1 ,-2)#, making angle of #45°# with the #x#-axis?

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Answer 1 · 2018-06-13T16:41:49

The equations of the lines can be:

#y=x-3" " or" " y=-x-1#

A line which makes an angle of #45°# with a horizontal line can have gradient of #1# or #-1#

#m=1 and (1,-2)# substituted into #y= mx+c# gives:

#-2 = (1)(1) +c#
#-2 = 1+c#
#-3=c#

The equation is # y= x-3#

#m=-1 and (1,-2)# substituted into #y= mx+c# gives:

#-2 = (-1)(1) +c#
#-2 = -1+c#
#-1=c#

The equation is # y= -x-1#