Home
Class 12
MATHS
A line y=mx+1 meets the circle (x-3)^(2)...

A line y=mx+1 meets the circle `(x-3)^(2)+(y+2)^(2)=25` at point P and Q. if mid point of PQ has abscissa of `-(3)/(5)` then value of m satisfies

A

`4 le mlt 6`

B

` -3 le m lt - 1`

C

` 2 le m lt 4`

D

`6le m lt 8`

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we will follow these steps: ### Step 1: Write the equations of the circle and the line The equation of the circle is given as: \[ (x - 3)^2 + (y + 2)^2 = 25 \] This represents a circle with center \(C(3, -2)\) and radius \(r = 5\). The equation of the line is given as: \[ y = mx + 1 \] ### Step 2: Find the midpoint of the points of intersection Let the points of intersection of the line and the circle be \(P\) and \(Q\). The midpoint \(M\) of \(PQ\) has an abscissa (x-coordinate) of \(-\frac{3}{5}\). ### Step 3: Substitute the x-coordinate into the line equation Substituting \(x = -\frac{3}{5}\) into the line equation to find the y-coordinate: \[ y = m\left(-\frac{3}{5}\right) + 1 = 1 - \frac{3m}{5} \] Thus, the coordinates of the midpoint \(M\) are: \[ M\left(-\frac{3}{5}, 1 - \frac{3m}{5}\right) \] ### Step 4: Determine the slope of line segment \(CR\) (where \(R\) is the midpoint) The slope of the line \(CR\) (from center \(C(3, -2)\) to midpoint \(M\)) is given by: \[ \text{slope of } CR = \frac{y_M - y_C}{x_M - x_C} = \frac{\left(1 - \frac{3m}{5}\right) - (-2)}{-\frac{3}{5} - 3} \] Calculating this gives: \[ = \frac{1 - \frac{3m}{5} + 2}{-\frac{3}{5} - \frac{15}{5}} = \frac{3 - \frac{3m}{5}}{-\frac{18}{5}} = \frac{3 - \frac{3m}{5}}{-\frac{18}{5}} = \frac{5(3 - \frac{3m}{5})}{-18} \] Simplifying further: \[ = \frac{15 - 3m}{-18} = \frac{3m - 15}{18} \] ### Step 5: Set up the relationship between slopes Since \(CR\) is perpendicular to \(PQ\), the product of their slopes must equal \(-1\). The slope of line \(y = mx + 1\) is \(m\). Therefore: \[ m \cdot \frac{3m - 15}{18} = -1 \] This simplifies to: \[ 3m^2 - 15m + 18 = 0 \] ### Step 6: Solve the quadratic equation Dividing the entire equation by 3: \[ m^2 - 5m + 6 = 0 \] Factoring gives: \[ (m - 2)(m - 3) = 0 \] Thus, the solutions for \(m\) are: \[ m = 2 \quad \text{or} \quad m = 3 \] ### Step 7: Conclusion The values of \(m\) that satisfy the condition are \(m = 2\) and \(m = 3\).
Doubtnut Promotions Banner Mobile Dark
|

Topper's Solved these Questions

  • CIRCLES

    VMC MODULES ENGLISH|Exercise JEE MAIN ( ARCHIVE )|29 Videos
  • BINOMIAL THEOREM

    VMC MODULES ENGLISH|Exercise JEE Archive|56 Videos
  • COMPLEX NUMBERS

    VMC MODULES ENGLISH|Exercise JEE ARCHIVE|76 Videos

Similar Questions

Explore conceptually related problems

The line 3x-2y=k meets the circle x^(2)+y^(2)=4r^(2) at only one point, if k^(2)=

The line y=mx+c intersects the circle x^(2)+y^(2)=r^(2) in two distinct points if

The straight-line y= mx+ c cuts the circle x^(2) + y^(2) = a^(2) in real points if :

If the line y=mx +1 meets the circle x^(2)+y^(2)+3x=0 in two points equidistant and on opposite sides of x-axis, then

The straight line x-2y+5=0 intersects the circle x^(2)+y^(2)=25 in points P and Q, the coordinates of the point of the intersection of tangents drawn at P and Q to the circle is

The straight line x-2y+1=0 intersects the circle x^(2)+y^(2)=25 in points P and Q the coordinates of the point of intersection of tangents drawn at P and Q to the circle is

A tangent to the parabola x^(2) = 4ay meets the hyperbola x^(2) - y^(2) = a^(2) in two points P and Q, then mid point of P and Q lies on the curve

If the line y = mx - (m-1) cuts the circle x^2+y^2=4 at two real and distinct points then total values of m are

If the straight line x - 2y + 1 = 0 intersects the circle x^2 + y^2 = 25 at points P and Q, then find the coordinates of the point of intersection of the tangents drawn at P and Q to the circle x^2 + y^2 = 25 .

If the straight line x - 2y + 1 = 0 intersects the circle x^2 + y^2 = 25 at points P and Q, then find the coordinates of the point of intersection of the tangents drawn at P and Q to the circle x^2 + y^2 = 25 .