A circle with equation x^2+y^2-2x+8y-40=0. Find the circle centre and the radius

2g=-2, -g=1. 2f=-8, -f=4. cc(-2,4). r=√(g^2+f^2-c)=√(4+16+40)=√80=4√5

LM

Related Maths A Level answers

All answers ▸

express x^2-4x+9 in the form (x-q)^2+y


x = 2t + 5, y = 3 + 4/t. a) Find dy/dx at (9.5) and b) find y in terms of x.


Find the tangent to the curve y = x^3 - 2x at the point (2, 4). Give your answer in the form ax + by + c = 0, where a, b and c are integers.


Use integration by parts to find the value of the indefinite integral (1/x^3)lnx ; integration with respect to dx