Find the point on the line y = 3x + 2 that is closest to the origin.
1 answer:
1.
the slope of the line y=3x+2 is the coefficient of x, that is 3.
2.
the slope of any line perpendicular to the line y=3x+2, is m, such that:
so
3.
so any line with equation y=-1/3x+k is perpendicular to y=3x+2.
moreover, the line y=-1/3x (so k=0) is the line passing through the origin
(0, 0) and perpendicular to y=3x+2
4. This means that the closest point of y=3x+2 to the origin is the intersection point of lines y=3x+2 and y=-1/3x
5.
to find this point:
3x+2=(-1/3)x
x(3+1/3)=-2
x(9/3+1/3)=-2
x*10/3=-2
thus y is : (-1/3)(-6/10)=0.2
Answer: (-0.6, 0.2)
the slope of the line y=3x+2 is the coefficient of x, that is 3.
2.
the slope of any line perpendicular to the line y=3x+2, is m, such that:
so
3.
so any line with equation y=-1/3x+k is perpendicular to y=3x+2.
moreover, the line y=-1/3x (so k=0) is the line passing through the origin
(0, 0) and perpendicular to y=3x+2
4. This means that the closest point of y=3x+2 to the origin is the intersection point of lines y=3x+2 and y=-1/3x
5.
to find this point:
3x+2=(-1/3)x
x(3+1/3)=-2
x(9/3+1/3)=-2
x*10/3=-2
thus y is : (-1/3)(-6/10)=0.2
Answer: (-0.6, 0.2)
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