TWO TOPICS

MAIN THINGS TO REMEMBER:

MIDPOINT:

DISTANCES:

GRADIENTS:

PERPENDICULR LINES HAVE TO GRADIENTS, WHICH MULTIPLY TO GIVE -1 i.e m1 x m2 = -1 m=gradient

TO FIND EQUATION OF LINE, FIND GRADIENT, THEN USE y − y₁ = m ( x − x₁) TO FIND THE OVERALL EQUATION.

GENERAL FORM OF A STRAIGHT LINE: y = mX + c where m=gradient, and c= y-intercept

POINTS OF INTERSECTION: SIMULTANEOUS EQUATIONS OR y1=y2

GENERAL FORM OF A CIRCLE EQUATION: (x-a)² + (y-b)² = r²

CIRCLE EQUATION WHICH HAS CENTRE (0,0): x² + y² = r²

TANGENT IS ALWAYS PERPENDICULAR TO CIRCLE AND CUTS AT ONE POINT ONLY

WHEN ANORMAL INTERSECTS CIRCLE, SIMULTANEOUS EQUALTIONS OR y1=y2