# maths

posted by .

Given that the equation of the circle is x^2 + y^2 +2x -8y+5 =0
(i)Find the centre and radius of the circle
(ii)Determine whether the line x-3y=8 is tangent to the given circle

• maths -

1. x^2+2x+(2/2)^2+Y^2-8y+(-8/2)^2=-5+1+16.
X^2+2x+1 + Y^2-8y+16 = 12.
(x+1)^2 + (y-4)^2 = 12.
(x-h)^2 + (y-k)^2 = r^2.

C(h,k).
C(-1,4).

r^2 = 12.
r = 2*sqrt3 = 3.46.

## Similar Questions

1. ### calc

standard equation of circle concentric with X^2+Y^2-2X-8Y+1=0 and tangent to line 2X-Y=3 Complete the squares to find the center of the circle. X^2+Y^2-2X-8Y+1=0 (x-1)^2+(y-4)^2 - 16 =0 The center is (1,4) and the radius for the given …
2. ### maths

1) Circle centre (7,-2) passes through (-2,10). Calculate radius and find equation of circle. 2) AB is diameter of circle A(9,5) B(-1,-7). Find equation of circle mid point. I know i have to use the eqn (x1+x2)/2 and (y1+y2)/2 3) Find …
3. ### steev

can u help this the qustion is : A circle passes through the points (1,4)&(5,0) and its centre lies on the line x+y-3=0.Find (i) the equation of the circle and it parametric equations . (ii) the centre,diameter and area of the circle …
4. ### math

can u help this the qustion is : A circle passes through the points (1,4)&(5,0) and its centre lies on the line x+y-3=0.Find (i) the equation of the circle and it parametric equations . (ii) the centre,diameter and area of the circle …
5. ### maths

Given that the equation of the circle is x^2+y^2+2x-8y+5=0 (i)find the centre and radius of the circle (ii)Determine whether the line x-3y=8 is tangent to the given circle
6. ### mathematics

The circle x2-2x+y2-4y-4=0 lies on the cartesian plane,question 2.1.1 equation of new circle which is the rotation of original circle through 180 degree around the origin...2.1.2 find equation of another circle which is the translation …
7. ### mathematics

The circle x2-2x+y2-4y-4=0 lies on the cartesian plane,question 2.1.1 equation of new circle which is the rotation of original circle through 180 degree around the origin...2.1.2 find equation of another circle which is the translation …
8. ### mathematics

The circle x2-2x+y2-4y-4=0 lies on the cartesian plane,question 2.1.1 equation of new circle which is the rotation of original circle through 180 degree around the origin...2.1.2 find equation of another circle which is the translation …
9. ### mathematics

The circle x2-2x+y2-4y-4=0 lies on the cartesian plane,question 2.1.1 equation of new circle which is the rotation of original circle through 180 degree around the origin...2.1.2 find equation of another circle which is the translation …
10. ### GEOMETRY CIRCLE

1.An isosceles triangle with each leg measuring 13 cm is inscribed in a circle . if the altitude to the base is 12 cm find the radius of the circle 2. Circles a and b are tangent at point c. p is on circle a and q is on circle b such …

More Similar Questions