a) Calculate the limit value to when
The point is to use Taylor or McLaurin polynomial..?.
B) Make a smilar task that will equal
And what happens to the x and 1 in x(cosx-1)? Same with the -x in sinx - x??
And how do you get that the cosx (mclaurin...) expression is approximately and the same with the sin expression?
Hope you have time for at least a brief explanation.
Now "put x = 0 in the expression" as you say it: