Answer:
When to lines intersect they create four angles. Each angle is opposite to another and form a pair of what are called opposite angles. Angles a and c are opposite angles. Angles b and d are opposite angles. Opposite angles are equal.
That is the Distributive property of equality
Dy/dx = (dy/dt) / (dx/dt)
dy/dt = 2cos(2t)
dx/dt = -2sin(2t)
dy/dx = 2cos(2t)/-2sin(2t) = -cot(2t)
d^y/dx^2 = d(-1/tan(2t))/dx = (tan(2t) * 0 - (-1)*2sec^2(2t))/tan^2(2t) = 2sec^2(2t)/tan^2(2t) = 2csc^2 (2t)
