Home
Class 11
MATHS
Statement-1: Reflection of the point (-3...

Statement-1: Reflection of the point (-3, 2) in the line x + y = 0 is (-2, 3).Statement-2: The reflection of a point `P(alpha,beta)` in the line ax+by+c=0 is the point `Q(alpha', beta')`if `((alpha+alpha')/2, (beta+beta')/2)` lies on the line

A

Statement -1 is True , Statement - 2 is true , Statement- 2 is a correct explanation for statement - 2

B

Statement-1 is True , Statement-2 is True , Statement -2 is not a correct explanation for Statement - 1 .

C

Statement-1 is True , Statement - 2 is False .

D

Statement - 1 is False , Statement -2 is True .

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to analyze the two statements provided and verify their correctness step by step. ### Step 1: Understanding Statement 2 Statement 2 states that the reflection of a point \( P(\alpha, \beta) \) in the line \( ax + by + c = 0 \) results in the point \( Q(\alpha', \beta') \) if the midpoint \( M \left( \frac{\alpha + \alpha'}{2}, \frac{\beta + \beta'}{2} \right) \) lies on the line. **Hint:** Remember that the midpoint of a segment is the average of the coordinates of the endpoints. ### Step 2: Finding the Midpoint Let \( P(\alpha, \beta) \) be the point and \( Q(\alpha', \beta') \) be its reflection. The midpoint \( M \) is given by: \[ M = \left( \frac{\alpha + \alpha'}{2}, \frac{\beta + \beta'}{2} \right) \] According to the statement, this midpoint must satisfy the line equation \( ax + by + c = 0 \). **Hint:** Substitute the coordinates of midpoint \( M \) into the line equation to check if it lies on the line. ### Step 3: Verifying Statement 1 Statement 1 claims that the reflection of the point \( (-3, 2) \) in the line \( x + y = 0 \) is \( (-2, 3) \). 1. **Identify the line:** The line \( x + y = 0 \) can be rewritten as \( y = -x \). 2. **Find the slope:** The slope of the line is \( -1 \). 3. **Find the slope of the line connecting \( P \) and \( Q \):** Since the reflection line is the mirror, the line connecting \( P \) and \( Q \) must be perpendicular to it. Therefore, the slope of line \( PQ \) should be \( 1 \) (the negative reciprocal of \( -1 \)). **Hint:** Use the point-slope form to find the equation of the line through \( P(-3, 2) \) with slope \( 1 \). ### Step 4: Finding the Intersection Point To find the intersection point \( M \) of the line \( PQ \) and the line \( x + y = 0 \): 1. **Equation of line \( PQ \):** \[ y - 2 = 1(x + 3) \implies y = x + 5 \] 2. **Set the equations equal to find \( M \):** \[ x + 5 = -x \implies 2x = -5 \implies x = -\frac{5}{2} \] \[ y = -\left(-\frac{5}{2}\right) = \frac{5}{2} \] Thus, \( M = \left(-\frac{5}{2}, \frac{5}{2}\right) \). **Hint:** Ensure that both lines intersect at the correct point by substituting back into both equations. ### Step 5: Using the Midpoint Formula Now, using the midpoint formula: \[ M = \left( \frac{-3 + \alpha'}{2}, \frac{2 + \beta'}{2} \right) \] Set this equal to \( M \): \[ \frac{-3 + \alpha'}{2} = -\frac{5}{2} \quad \text{and} \quad \frac{2 + \beta'}{2} = \frac{5}{2} \] From these equations, solve for \( \alpha' \) and \( \beta' \): 1. From the first equation: \[ -3 + \alpha' = -5 \implies \alpha' = -2 \] 2. From the second equation: \[ 2 + \beta' = 5 \implies \beta' = 3 \] **Hint:** Check your calculations to ensure that the values obtained for \( \alpha' \) and \( \beta' \) match the reflection point given in Statement 1. ### Conclusion Since we have verified that the reflection of point \( (-3, 2) \) in the line \( x + y = 0 \) is indeed \( (-2, 3) \), both statements are true. Therefore, Statement 2 correctly explains Statement 1. **Final Answer:** Both Statement 1 and Statement 2 are true, and Statement 2 is the correct explanation for Statement 1.

To solve the problem, we need to analyze the two statements provided and verify their correctness step by step. ### Step 1: Understanding Statement 2 Statement 2 states that the reflection of a point \( P(\alpha, \beta) \) in the line \( ax + by + c = 0 \) results in the point \( Q(\alpha', \beta') \) if the midpoint \( M \left( \frac{\alpha + \alpha'}{2}, \frac{\beta + \beta'}{2} \right) \) lies on the line. **Hint:** Remember that the midpoint of a segment is the average of the coordinates of the endpoints. ### Step 2: Finding the Midpoint ...
Promotional Banner

Topper's Solved these Questions

  • STRAIGHT LINES

    OBJECTIVE RD SHARMA ENGLISH|Exercise SECTION - II (ASSERTION - REASON TYPE MCQs|1 Videos
  • STRAIGHT LINES

    OBJECTIVE RD SHARMA ENGLISH|Exercise Exercise|130 Videos
  • STRAIGHT LINES

    OBJECTIVE RD SHARMA ENGLISH|Exercise Section-1 Solved MCQs (Example)|1 Videos
  • SETS

    OBJECTIVE RD SHARMA ENGLISH|Exercise Chapter Test|30 Videos

Similar Questions

Explore conceptually related problems

Statement I Reflection of the point (5,1) in the line x+y=0 is (-1,-5) Statement II Reflection of a point P(alpha,beta) in the line ax+by+c= 0 is Q (alpha',beta' ) " if " ((alpha +alpha')/2 ,(beta +beta' )/2) lies on the line .

I If a point (alpha, beta) lies on the circle x^2 +y^2=1 then the locus of the point (3alpha.+2, beta), is

The point of intersection of lines is (alpha, beta) , then the equation whose roots are alpha, beta , is

If alpha, beta are the roots of the equation ax^2 + bx +c=0 then the value of (1+alpha+alpha^2)(1+beta+beta^2) is

The image of the point A (1,2) by the line mirror y=x is the point B and the image of B by the line mirror y=0 is the point (alpha,beta) , then a. alpha=1,beta=-2 b. alpha = 0,beta=0 c. alpha=2,beta=-1 d. none of these

the image of the point A(2,3) by the line mirror y=x is the point B and the image of B by the line mirror y=0 is the point (alpha,beta), find alpha and beta

If alpha , beta are the roots of ax ^2 + bx +c=0 then alpha ^5 beta ^8 + alpha^8 beta ^5=

If alpha , beta are the roots of ax^(2) + bx +c=0 , then (alpha^(3) + beta^(3))/(alpha^(-3) + beta^(-3)) is equal to :

If alpha,beta be the roots of x^(2)-a(x-1)+b=0 , then the value of (1)/(alpha^(2)-a alpha)+(1)/(beta^(2)-a beta)+(2)/(a+b) is

If alpha , beta are the roots of x^2 +x+1=0 then alpha beta + beta alpha =