`x=a(cos t + log tan t/2), y =a sin t`

If x=a(cos t+(log tan)(1)/(2)),y=a sin t then (dy)/(dx) is equal to

If x = a (cos t + t sin t), y = a (sin t - t cos t), then at t = pi//4,(dy)/(dx)

If x=cos t+(log tan t)/(2),y=sin t, then find the value of (d^(2)y)/(dt^(2)) and (d^(2)y)/(dx^(2)) at t=(pi)/(4)

If x=cos t+(log tan t)/(2),y=sin t, then find the value of (d^(2)y)/(dt^(2)) and (d^(2)y)/(dx^(2))a=(pi)/(4)

x = a (cos t + sin t), y = a (sin t-cos t)

x=a cos t, y=b sin t

If x=a sin t and y=a(cos t+(log tan t)/(2)) find (d^(2)y)/(dx^(2))