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Tangents drawn from point of intersectio...

Tangents drawn from point of intersection A of circles `x^2+y^2=4 and (x-sqrt3)^2+(y-3)^2= 4` cut the line joinihg their centres at B and C Then triangle BAC is

A

equilateral triangle

B

right angle triangle

C

obtuse angle triangle

D

isosceles triangle and `/_ABC = (pi)/(6)`

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To solve the problem, we need to analyze the given circles and the tangents drawn from their point of intersection. Let's break down the solution step by step. ### Step 1: Identify the equations of the circles The equations of the circles are: 1. \( x^2 + y^2 = 4 \) (Circle 1) 2. \( (x - \sqrt{3})^2 + (y - 3)^2 = 4 \) (Circle 2) ### Step 2: Find the centers and radii of the circles - The center of Circle 1 is at \( (0, 0) \) with a radius of \( 2 \) (since \( r^2 = 4 \)). - The center of Circle 2 is at \( (\sqrt{3}, 3) \) with a radius of \( 2 \) (since \( r^2 = 4 \)). ### Step 3: Find the points of intersection of the circles To find the points of intersection, we can substitute \( y^2 = 4 - x^2 \) from Circle 1 into Circle 2's equation: \[ (x - \sqrt{3})^2 + (4 - x^2 - 3)^2 = 4 \] This simplifies to: \[ (x - \sqrt{3})^2 + (1 - x^2)^2 = 4 \] Expanding and solving this equation will yield the points of intersection. ### Step 4: Calculate the angle between the tangents Let \( A \) be the point of intersection of the two circles. The tangents drawn from point \( A \) to both circles will form an angle \( \theta \) at point \( A \). The formula for the angle \( \theta \) between the tangents from point \( A \) to the circles can be derived using the cosine rule: \[ \cos \theta = \frac{r_1^2 + r_2^2 - d^2}{2r_1r_2} \] where \( r_1 \) and \( r_2 \) are the radii of the circles, and \( d \) is the distance between the centers of the circles. ### Step 5: Calculate the distance between the centers The distance \( d \) between the centers \( (0, 0) \) and \( (\sqrt{3}, 3) \) is: \[ d = \sqrt{(\sqrt{3} - 0)^2 + (3 - 0)^2} = \sqrt{3 + 9} = \sqrt{12} = 2\sqrt{3} \] ### Step 6: Substitute values into the cosine formula Substituting \( r_1 = 2 \), \( r_2 = 2 \), and \( d = 2\sqrt{3} \) into the cosine formula gives: \[ \cos \theta = \frac{2^2 + 2^2 - (2\sqrt{3})^2}{2 \cdot 2 \cdot 2} \] \[ = \frac{4 + 4 - 12}{8} = \frac{-4}{8} = -\frac{1}{2} \] This means \( \theta = \frac{2\pi}{3} \) (or \( 120^\circ \)). ### Step 7: Determine the type of triangle Since the angle \( \theta \) between the tangents is \( 120^\circ \), the angles \( \angle BAC \) and \( \angle ABC \) can be determined. The triangle \( BAC \) is formed by the points \( A \), \( B \), and \( C \) where \( B \) and \( C \) are the points where the tangents intersect the line joining the centers. Given that one angle is greater than \( 90^\circ \), triangle \( BAC \) is an obtuse triangle. ### Conclusion The triangle \( BAC \) is an obtuse triangle.

To solve the problem, we need to analyze the given circles and the tangents drawn from their point of intersection. Let's break down the solution step by step. ### Step 1: Identify the equations of the circles The equations of the circles are: 1. \( x^2 + y^2 = 4 \) (Circle 1) 2. \( (x - \sqrt{3})^2 + (y - 3)^2 = 4 \) (Circle 2) ### Step 2: Find the centers and radii of the circles ...
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