A circle C has centre (-5, 12) and passes through the point (0,0) Find the second point where the line y=x intersects the circle.

The equation of a circle comes in a standard format of (x-a)2 + (y-b)2 = r2 where (a, b) are the coordinates of the centre of the circle and r is the radiusFrom the information, we can find the radius of the circle (a diagram is useful) by finding the distance between the centre point and a point on the circle. Hence we can use the distance between (-5,12) and (0,0).Using Pythagoreas, the distance is ((x-x)2 + (y-y)2)1/2 Hence the radius2 is (0--5)2 + (0-12)2 i.e. r2 = 169 and r = 13Hence the equation of the circle is (x+5)2 + (y-12)2 = 169
The next part would involve finding the other intersection with the circle. Therefore we need the solutions to the simultaneous equations y= x and (x+5)2 + (y-12)2 = 169. Achieve this by substituting substituting in x for y (as y=x)Hence (x+5)2+(x-12)2=169Expanding this: x2 + 10x + 25 + x2 -24x + 144 = 1692x2-14x+169 = 169So 2x2-14x = 0x2-7x = 0Factorise thisx(x-7) = 0Hence x = 0 or x = 7Using y = x, the points of intersection are (0,0) and (7,7).(0,0) is given so the other point is (7,7).

Answered by Maths tutor

5207 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

The polynomial p(x) is given by p(x)=x^3 - 5x^2 - 8x + 48. Given (x+3) is a factor of p(x), express p(x) as a product of 3 linear factors.


given that y = 1 when x = π, find y in terms of x for the differential equation, dy/dx = xycos(x)


Find a local minimum of the function f(x) = x^3 - 2x.


Find the area bounded by the curve x^3-3x^2+2x and the x-axis between x=0 and x=1.


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences