Tag: coordinates, points and lines

Questions Related to coordinates, points and lines

If the line $(2x+y+1)+\lambda(x-y+1)=0$ is parallel to $y-axis$ then value of $\lambda$ is ?
  1. $1$

  2. $-1$

  3. $\dfrac{1}{2}$

  4. $2$


Correct Option: A
Explanation:
Parallel to y-axis $\Rightarrow y=0$
$2x+y+1+\lambda x-\lambda y+\lambda =0$
$x(2+\lambda )+y(1-\lambda )+(1+\lambda )=0$
coefficient of $y=0$
$1-\lambda =0\Rightarrow \lambda =1$

The equation of the line passing through $(-4, 3)$, parallel to the $3x+7y+6=0$

  1. 3x+7y-9=0

  2. 3x+7y+9=0

  3. 3x+7y+3=0

  4. 3x+7y+12=0


Correct Option: A
Explanation:

The line parallel to $3x+7y+6=0$ is $3x+7y+k=0$

It passes through $(-4,3)$
$\implies 3(-4)+7(3)+k=0\-12+21+k=0\\implies k=-9$
So the required equation is $3x+7y-9=0$

The slope and  the y-intercept  of the given line, $y-3x -6=0$ are respectively,

  1. $3, -6$

  2. $-3, -6$

  3. $3, 6$

  4. $-3, 6$


Correct Option: C
Explanation:

The given equation is $y-3x-6=0$ ........ $(1)$


To obtain the slope and $y-$intercept of the given equation, we write it in slope-intercept form which is 


$y=mx+c$, where $m$ and $c$ are slope and $y-$intercept

From $(1)$,

$y-3x-6=0\implies y=3x+6$

Comparing it with $y=mx+c$ we get,

slope$=m=3$ and y-intercept$=c=6$

Hence, option C is correct.

The slope and y-intercept of the following line are respectively

$2y + 2x - 5 = 0$

  1. $ slope=m=1\quad and\quad y-intercept=c=\frac { 5 }{ 2 } . $

  2. $ slope=m=1/5\quad and\quad y-intercept=c=\frac { 2 }{ 5 } . $

  3. $ slope=m=-1\quad and\quad y-intercept=c=\frac { 5 }{ 2 } . $

  4. $ slope=m=-1/5\quad and\quad y-intercept=c=\frac { 2 }{ 5 } . $


Correct Option: C
Explanation:

The given equation is $2y+2x-5=0$ ........ $(1)$

To obtain the slope and $y-$intercept of the given equation, we write it in slope-intercept form which is 
$y=mx+c$, where $m$ and $c$ are slope and $y-$intercept

From $(1)$,
$2y+2x-5=0\implies y=-x+\dfrac{5}{2}$
Comparing it with $y=mx+c$ we get,
slope$=m=-1$ and y-intercept$=c=\dfrac{5}{2}$
Hence, option C is correct.

The slope and y-intercept of the following line are respectively

$7x-y + 3 =0$

  1. $ slope=m=7/3\quad and\quad y-intercept=1.\ $

  2. $ slope=m=-7\quad and\quad y-intercept=3.\ $

  3. $ slope=m=-7/3\quad and\quad y-intercept=1.\ $

  4. $ slope=m=7\quad and\quad y-intercept=3.\ $


Correct Option: D
Explanation:

The given equation is $7x-y+3=0$ ........ $(1)$

To obtain the slope and $y-$intercept of the given equation, we write it in slope-intercept form which is 
$y=mx+c$, where $m$ and $c$ are slope and $y-$intercept

From $(1)$,
$7x-y+3=0\implies y=7x+3$
Comparing it with $y=mx+c$ we get,
slope$=m=7$ and y-intercept$=c=3$
Hence, option D is correct.

The slope and  the y-intercept  of the given line, $2x-3y = 7$ are respectively,

  1. $\dfrac{3}{2}, \dfrac{-3}{7}$

  2. $\dfrac{2}{3}, \dfrac{-7}{3}$

  3. $\dfrac{3}{2},  \dfrac{3}{7}$

  4. $\dfrac{2}{3}, \dfrac{7}{3}$


Correct Option: B
Explanation:

The given equation is $2x-3y=7$ ........ $(1)$


To obtain the slope and $y-$intercept of the given equation, we write it in slope-intercept form which is, 

$y=mx+c$, where $m$ and $c$ are slope and $y-$intercept

From $(1)$,

$2x-3y=7\implies 3y=2x-7\implies y=\dfrac{2}{3} x+\left( -\dfrac{7}{3}  \right)$

Comparing it with $y=mx+c$ we get,

slope$=m=\dfrac{2}{3}$ and y-intercept$=c=-\dfrac{7}{3}$

Hence, option B is correct.

The slope and y-intercept of the following line are respectively

$4x-y=0$

  1. $ slope=m=4\quad and\quad y-intercept=0.\ $

  2. $ slope=m=-4\quad and\quad y-intercept=0.\ $

  3. $ slope=m=1/4\quad and\quad y-intercept=0.\ $

  4. $ slope=m=0\quad and\quad y-intercept=1/4.\ $


Correct Option: A
Explanation:

The given equation is $4x-y=0$ ........ $(1)$

To obtain the slope and $y-$intercept of the given equation, we write it in slope-intercept form which is 
$y=mx+c$, where $m$ and $c$ are slope and $y-$intercept

From $(1)$,
$4x-y=0\implies y=4x$
Comparing it with $y=mx+c$ we get,
slope$=m=4$ and y-intercept$=c=0$
Hence, option A is correct.

The slope and y-intercept of the following line are respectively

$8x-4y-1=0$

  1. $ slope=m=\frac { -1 }{ 2 } \quad and\quad y-intercept=\frac { 1 }{ 4 } . $

  2. $ slope=m=2 \quad and\quad y-intercept=-\frac { 1 }{ 4 } . $

  3. $ slope=m=-\frac { 1 }{ 2 } \quad and\quad y-intercept=-\frac { 1 }{ 4 } . $

  4. $ slope=m=\frac { 1 }{ 2 } \quad and\quad y-intercept=\frac { 1 }{ 4 } . $


Correct Option: B
Explanation:
Given line
$8x-4y-1=0$
Comparing above eq with $y=mx+c$ where m is slope and c is y intercept
Here $m=2,c=-\dfrac{1}{4}$

The slope and y-intercept of the following line are respectively

$5x - 2y = 3$

  1. $ slope=m=-\frac { 5 }{ 2 } \quad and\quad y-intercept=-\frac { 3 }{ 2 } . $

  2. $ slope=m=\frac { 5 }{ 2 } \quad and\quad y-intercept=\frac { 3 }{ 2 } . $

  3. $ slope=m=\frac { 5 }{ 2 } \quad and\quad y-intercept=-\frac { 3 }{ 2 } . $

  4. $ slope=m=-\frac { 5 }{ 2 } \quad and\quad y-intercept=\frac { 3 }{ 2 } . $


Correct Option: C
Explanation:

The given equation is $5x-2y=3$ ........ $(1)$

To obtain the slope and $y-$intercept of the given equation, we write it in slope-intercept form which is 
$y=mx+c$, where $m$ and $c$ are slope and $y-$intercept

From $(1)$,
$5x-2y=3\implies y=\dfrac{5}{2}x - \dfrac{3}{2}$
Comparing it with $y=mx+c$ we get,
slope$=m=\dfrac{5}{2}$ and y-intercept$=c=-\dfrac{3}{2}$
Hence, option C is correct.

The slope and $y$-intercept of the following line are respectively

$5x-8y =-2$

  1. slope $=m=-\dfrac { 5 }{ 8 } $ and $ y$-intercept $=\dfrac { 1 }{ 4 }  $

  2. slope $=m=\dfrac { 5 }{ 8 } $ and $y$-intercept $=-\dfrac { 1 }{ 4 }  $

  3. slope $=m=-\dfrac { 5 }{ 8 }$ and $ y$-intercept $=-\dfrac { 1 }{ 4 }  $

  4. slope $=m=\dfrac { 5 }{ 8 } $ and $ y$-intercept $=\dfrac { 1 }{ 4 }  $


Correct Option: D
Explanation:

$ To\quad obtain\quad the\quad slope\quad and\quad y-intercept\quad of\quad an\quad equation\quad of\quad any\quad form\ write\quad it\quad in\quad slope-intercept\quad form\quad which\quad is\quad y=mx+c.\ Then\quad slope=m\quad and\quad y-intercept=c.\  $
The given equation is: $5x - 8y = -2$
$-8y = -5x - 2$
$y = \dfrac{5}{8}x + \dfrac{2}{8} $
Compare it with general form of equation: $y = mx + c$
m = $\dfrac{5}{8}$, y - intercept = c = $  \dfrac{1}{4}$