$($a$)(10$ marks$)$ Sketch thesurfacewith a$,$ h and L strictly positive real constants. You can produce the sketch by hand or by using a computer program. In this latter case, please specify what program you have used and write the commands that you have issued to generate the plot $($you can do this by including a screenshot$).$ In either case, you must explain your answer and not just draw the surface.$($b$)(20$ marks$)$ Show that the area of the surface is given by the integralAreaH$0$where u $=!$I. You shouldidentify the parameters H and A in terms of the parameters that appear in equation $(3).$ You are not requested to evaluate the integral.