line p in the x-axis

[sanju09]

If the equation of a line p in the coordinate plane is y = 3 x + 2, what is the equation of line q which is a reflection of line p in the x-axis?
A. y = -3 x + 2
B. y = -3 x - 2
C. y = 3 x - 2
D. y = -1/3 x - 5
E. y = -1/3 x + 5

[selango]

y=3x+2

(x,y)=(-2/3,2)

Relection in x axis (2/3,2)

y=-3x+2

Pick A

[Hussain15]

"C" is my pick. Whats the OA??

[sanju09]

"C" is my pick. Whats the OA??

When it came to me, I assumed a line with its rise being 3 times as much as its run and the intercept on y-axis being 2 in positive.

When a line is reflected in the x-axis, its intercept on y-axis changes sign only, eliminate A, D, and E; but the intercept on x-axis remains same. This must result in the slope also changing sign only. Now pick B

[selango]

Sanju,

If the line is reflected on x axis,it either in first or second quadrant..right?

Here the line is in 1st quadrant.Then the reflection must be in 2nd quadrant.

Pls clarify.

[sanju09]

Sanju,

If the line is reflected on x axis,it either in first or second quadrant..right?

Here the line is in 1st quadrant.Then the reflection must be in 2nd quadrant.

Pls clarify.

How can we call a line to be limited to any quadrant, it's the point that could be in any quadrant. A line is free to trespass the borders called the axes.

Try to draw out what I said in the above post, on a rectangular plane, creep through the choices to eliminate few, ask for graphics if doubt remains.

[selango]

Sanju,

If the line is reflected on x axis,it either in first or second quadrant..right?

Here the line is in 1st quadrant.Then the reflection must be in 2nd quadrant.

Pls clarify.

How can we call a line to be limited to any quadrant, it's the point that could be in any quadrant. A line is free to trespass the borders called the axes.

Try to draw out what I said in the above post, on a rectangular plane, creep through the choices to eliminate few, ask for graphics if doubt remains.

Can you please explain this with a diagram.

The line y=3x+2 is in second quadrant..rt?

[sanju09]

Sanju,

If the line is reflected on x axis,it either in first or second quadrant..right?

Here the line is in 1st quadrant.Then the reflection must be in 2nd quadrant.

Pls clarify.

How can we call a line to be limited to any quadrant, it's the point that could be in any quadrant. A line is free to trespass the borders called the axes.

Try to draw out what I said in the above post, on a rectangular plane, creep through the choices to eliminate few, ask for graphics if doubt remains.

Can you please explain this with a diagram.

The line y=3x+2 is in second quadrant..rt?

only a part of it is in the 2nd quadrant

[outreach]

@selango

reflection in X axis means y value will have opposite sign
Reflection in x axis (-2/3,-2)

HENCE B Shd be the answer

y=3x+2

(x,y)=(-2/3,2)

Relection in x axis (2/3,2)

y=-3x+2

Pick A