1.
Let x(t)=22costsin2tx(t) = 2\sqrt{2} \cos t \sqrt{\sin 2t} and y(t)=22sintsin2ty(t) = 2\sqrt{2} \sin t \sqrt{\sin 2t}, t(0,π2)t \in \left(0, \frac{\pi}{2}\right). Then 1+(dydx)2d2ydx2\frac{1 + \left(\frac{dy}{dx}\right)^2}{\frac{d^2y}{dx^2}} at t=π4t = \frac{\pi}{4}
is equal to