Determine the algebraic rewrite that most directly facilitates evaluating the limit x→0limx21−cosx. Which of the following substitutions is MOST appropriate?
a) Rewrite 1−cosx as sin2x
b) Rewrite 1−cosx as 2sin22x
c) Rewrite 1−cosx as 2sin2x
d) Rewrite 1−cosx as 2x2