Question

lim as x approaches pi/4 from sin4x*cos2x/(x-pi/4)^2

Answer 1

try the substitution
x=pi/4 = y

Answer 2

x- pi/4 = y

Answer 3

and then?

Answer 4

find

sin 4x and cos2x
in terms of y

Answer 5

since
x= y+pi/4

what will be sin4x =... ?

Answer 6

should i expand sin4x and cos 2x first or? what should i do?