Problems 1 -3. Write the equation for each surface. You don't need to redraw the graph. 1 ) 2) (Note: Radius = 2) 3) Z Problems 4 - 13. Sketch each surface. 4) x2+ y+z' =81 9) z=\\81-x2 - yz 5) 2x+3y+5z =30 10) Z =25-x2 - y2 6) z=x+y 11) y =16-z 7) x2 + y = 36 12) y = sin z 8) Z= x- 13) zzyz -x2 (Try this. (3 )