Home
Class 12
MATHS
Consider the circle x^2+y^2=9 and the pa...

Consider the circle `x^2+y^2=9` and the parabola `y^2=8x`. They intersect at P and Q in the first and fourth quadrants, respectively. Tangents to the circle at P and Q intersect the X-axis at R and tangents to the parabola at P and Q intersect the X-axis at S.
The ratio of the areas of `trianglePQS" and "trianglePQR` is

A

`1: sqrt(2)`

B

`1 : 2`

C

`1 : 4`

D

`1 : 8`

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to find the points of intersection of the given circle and parabola, determine the points where the tangents intersect the x-axis, and then calculate the areas of the triangles formed. ### Step 1: Find the Points of Intersection The equations of the circle and the parabola are: 1. Circle: \( x^2 + y^2 = 9 \) 2. Parabola: \( y^2 = 8x \) Substituting \( y^2 = 8x \) into the circle's equation: \[ x^2 + 8x = 9 \] Rearranging gives: \[ x^2 + 8x - 9 = 0 \] Now, we can solve this quadratic equation using the quadratic formula: \[ x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} = \frac{-8 \pm \sqrt{64 + 36}}{2} = \frac{-8 \pm 10}{2} \] Calculating the roots: \[ x_1 = 1 \quad \text{and} \quad x_2 = -9 \] Now, substituting \( x = 1 \) back into the parabola's equation to find \( y \): \[ y^2 = 8(1) = 8 \implies y = \pm 2\sqrt{2} \] Thus, the points of intersection are: - \( P(1, 2\sqrt{2}) \) in the first quadrant - \( Q(1, -2\sqrt{2}) \) in the fourth quadrant ### Step 2: Find the Tangents to the Circle The equation of the tangent to the circle at point \( P(1, 2\sqrt{2}) \) is given by: \[ x_1x + y_1y = 9 \implies 1 \cdot x + 2\sqrt{2} \cdot y = 9 \] Rearranging gives: \[ x + 2\sqrt{2}y - 9 = 0 \] To find where this tangent intersects the x-axis (\( y = 0 \)): \[ x - 9 = 0 \implies x = 9 \implies R(9, 0) \] For point \( Q(1, -2\sqrt{2}) \): \[ 1 \cdot x - 2\sqrt{2} \cdot y = 9 \implies x - 2\sqrt{2}y - 9 = 0 \] Setting \( y = 0 \): \[ x - 9 = 0 \implies x = 9 \implies R(9, 0) \] ### Step 3: Find the Tangents to the Parabola The equation of the tangent to the parabola at point \( P(1, 2\sqrt{2}) \) is: \[ yy_1 = 4(x + x_1) \implies y(2\sqrt{2}) = 4(x + 1) \] Rearranging gives: \[ 2\sqrt{2}y - 4x - 4 = 0 \] Setting \( y = 0 \): \[ -4x - 4 = 0 \implies x = -1 \implies S(-1, 0) \] For point \( Q(1, -2\sqrt{2}) \): \[ y(-2\sqrt{2}) = 4(x + 1) \implies -2\sqrt{2}y - 4x - 4 = 0 \] Setting \( y = 0 \): \[ -4x - 4 = 0 \implies x = -1 \implies S(-1, 0) \] ### Step 4: Calculate the Areas of Triangles **Area of Triangle \( PQS \):** - Base \( PS = 2 \) (from \( P(1, 2\sqrt{2}) \) to \( S(-1, 0) \)) - Height = \( 2\sqrt{2} \) Area: \[ \text{Area}_{PQS} = \frac{1}{2} \times \text{base} \times \text{height} = \frac{1}{2} \times 2 \times 2\sqrt{2} = 2\sqrt{2} \] **Area of Triangle \( PQR \):** - Base \( PR = 8 \) (from \( P(1, 2\sqrt{2}) \) to \( R(9, 0) \)) - Height = \( 2\sqrt{2} \) Area: \[ \text{Area}_{PQR} = \frac{1}{2} \times 8 \times 2\sqrt{2} = 8\sqrt{2} \] ### Step 5: Find the Ratio of Areas The ratio of the areas of triangle \( PQS \) to triangle \( PQR \): \[ \text{Ratio} = \frac{\text{Area}_{PQS}}{\text{Area}_{PQR}} = \frac{2\sqrt{2}}{8\sqrt{2}} = \frac{1}{4} \] ### Final Answer The ratio of the areas of triangle \( PQS \) and triangle \( PQR \) is \( \frac{1}{4} \).
Promotional Banner

Similar Questions

Explore conceptually related problems

Consider the circle x^2 + y^2 = 9 and the parabola y^2 = 8x. They intersect at P and Q in first and 4th quadrant,respectively. Tangents to the circle at P and Q intersect the x-axis at R and tangents at the parabola at P and Q intersect the x-axis at S.

Consider the ellipse x^2/9+y^2/4=1 and the parabola y^2 = 2x. They intersect at P and Q In the first andfourth quadrants respectively. Tangents to the ellipse at P and Q intersect the x-axis at R and tangents to the parabola at P and Q intersect the x-axis at S The ratio of the areas of the triangles PQS and PQR, is

Consider the ellipse x^2/9+y^2/4=1 and the parabola y^2 = 2x They intersect at P and Q in the first andfourth quadrants respectively. Tangents to the ellipse at P and Q intersect the x-axis at R and tangents tothe parabola at P and Q intersect the x-axis at S.The ratio of the areas of the triangles PQS and PQR, is

Consider the curves C_(1):|z-2|=2+Re(z) and C_(2):|z|=3 (where z=x+iy,x,y in R and i=sqrt(-1) .They intersect at P and Q in the first and fourth quadrants respectively.Tangents to C_(1) at P and Q intersect the x- axis at R and tangents to C_(2) at P and Q intersect the x -axis at S .If the area of Delta QRS is lambda sqrt(2) ,then find the value of (lambda)/(2)

Let the line y = mx intersects the curve y^2 = x at P and tangent to y^2 = x at P intersects x-axis at Q. If area ( triangle OPQ) = 4, find m (m gt 0) .

The tangent at P( at^2, 2at ) to the parabola y^(2)=4ax intersects X axis at A and the normal at P meets it at B then area of triangle PAB is

Let F_1(x_1,0) and F_2(x_2,0), for x_1 0, be the foci of the ellipse x^2/9+y^2/8=1 Suppose a parabola having vertex at the origin and focus at F_2 intersects the ellipse at point M in the first quadrant and at point N in the fourth quadrant. If the tangents to the ellipse at M and N meet at R and the normal to the parabola at M meets the x-axis at Q, then the ratio of area of the triangle MQR to area of the quadrilateral MF_1 NF_2 is

if the tangent to the parabola y=x(2-x) at the point (1,1) intersects the parabola at P. find the co-ordinate of P.

A line intersects the y-axis and x-axis at the points P and Q respectively. If (2,-5) is the mid-point of PQ then find the coordinates of P and Q.