It needs to be in the language R, thanks!

(c)Letf1(x)=x,F2(x)=x,3(x)=e, andf 4(x)=e . Plot the curves of the four functions together for x (-1,1]. You need to have a legend to state these functions. (d) Plot the curve of function f(O)=cos(O)+sin(20) for [0,21]. You need to express the horizontal axis by 0 and the vertical axis by f(0) = cos(0) + sin(20). (c)Letf1(x)=x,F2(x)=x,3(x)=e, andf 4(x)=e . Plot the curves of the four functions together for x (-1,1]. You need to have a legend to state these functions. (d) Plot the curve of function f(O)=cos(O)+sin(20) for [0,21]. You need to express the horizontal axis by 0 and the vertical axis by f(0) = cos(0) + sin(20)