A curve is defined by the parametric equations x=tet and y=lnt+t2, where t>0.
a. (i) Find dtdx and dtdy.
b. (ii) Hence obtain a simplified expression for dxdy in terms of t.
c. (iii) Evaluate dxdy at t=1.
d. (iv) Using the value from part (iii), state whether the curve is rising or falling with respect to x at the point corresponding to t=1. Justify your answer briefly.