Расчётные задания по высшей математике, вариант 21

I. To investigate the function and construct its graph.
21. a) b)

II. 21. From the strip sheet width 11cm is required to make an open-topped trough, the cross-section of which must be in the form ravnoboch¬noy trapeze. The bottom of the trough has a width of 7 cm. What should be the width of the chute at the top, so that it could accommodate the largest amount of water?

III. Write the general equation of the plane tangent to the surface at the specified point Mo.
The surface defined implicitly.
21. Mo.

IV. Calculate the limits of the functions:
21. a). b).

V. Find the minimum and maximum values \u200b\u200bof the functions in the area.
21,,,.