If f(x)=cxnf(x) = cx^nf(x)=cxn, what is f′(x)f'(x)f′(x) by the power rule?
cnxn−1cnx^{n-1}cnxn−1
cxn−1cx^{n-1}cxn−1
cnxncnx^ncnxn
c(n−1)xn−1c(n-1)x^{n-1}c(n−1)xn−1