xy==16−????2????3−16???? is symmetric about the x-axis. (If ???? gives us the point (x,y), then −???? will give (x,−y) ). At which x value is the tangent to this curve horizontal? x= 32/3 . At which ???? value is the tangent to this curve vertical? ????= 0 . The curve makes a loop which lies along the x-axis. What is the total area inside the loop?