$1-$ Write a python program that plots the following $4$ functions in one graph using the subplot command and matplotlib package. Include legend, title, grid, $x$ label, and $y$ label. The range of $x$ is $-10$ to $+10$ with $1000$ samples.

a$.f(x)=x^2$ red color

b$.g(x)=x^3$ blue color

c$.k(x)=sin(x)$ magenta color

d$.l(x)=2^{(-x+1)}$ yellow color

Hint: Final answer should look like below: