It needs a process to find the limit x → 0 LIM (1-cos ax) / sin ^ 2x (a is a constant)

It needs a process to find the limit x → 0 LIM (1-cos ax) / sin ^ 2x (a is a constant)

x→0 lim (1-cos ax)/(sinx)^2
=x→0 lim (a*sin ax)/(2sinx*cosx)
=x→0 lim (a*sin ax)/sin2x
=x→0 lim (a^2*cos ax)/2cos2x
=(a^2*1)/(2*1)
=(a^2)/2
Just use the lobita rule twice