Advanced Modelling and Simultaneous Equations
Simultaneous equations involving quadratics create intersection problems between curves and lines. When solving y=x2−5x+4 and y=x−1, you're finding where a parabola meets a straight line. The number of solutions tells you how many intersection points exist.
Tangent conditions occur when the discriminant equals zero. For a line y=x+c to touch (be tangent to) a curve, there must be exactly one intersection point. This gives you the condition to find the value of c.
Projectile modelling extends to golf balls and other real situations. The trajectory passing through (0,0), (50,20), and (100,0) creates the equation H=−1251(x−50)2+20, showing the classic parabolic flight path.
Model limitations are equally important - assuming flat ground, ignoring air resistance, or neglecting spin effects are typical restrictions you should always consider.
Key Tip: When finding tangent conditions, remember that tangency means the discriminant equals zero - one solution only.