Matplotlib in-built functions that are used:

plot() - to plot the continuous fn
xlabel() - to name the x-axis.
ylabel() - to name the y-axis.
title() - to give heading to the graph
show() - to display the plotted graph in a window.
scatter() - points of scatter plot
xlim() - limits of x axis
show() - to display the plotted graph in a window.
bar() - is used to plot bar plot vertically (default)
barh() - function helps to make a horizontal bar plot.
axvline() - adds a vertical line across axis
axhline() - adds a horizontal line across axis
pie() - assign the arguments of pie chart