6. (20 points) State the code for the following a) Plot the function f(x)=x-asin(r) for a from - tor (use linspace with 50 points). Define the line style as black color and dash line and add marker circle. b) Plot the function f(x, y) = sin( + y + xy)/ + y + 1 for x, y (-10, 10] with increment 0.1 (Plot mesh). c) By using subplot, obtain the following figure, where the first figure is the graph of y = zsin z with red color and dash line and the second one is the graph of = cos z with blue color and dash-dot line in the interval re [-, *] with increment 0.01. A 1.8 DE