Find the limit of f(x) as x approaches 0.
f(x) = [1-cos^2(3x)] / x^2
Is there a way to do this if we haven't learned L'Hopital's rule yet?
Can we rewrite 1-cos^2(3x) as sin^2(3x), and then use the basic limit: lim x→0 sin(x) / x = 1?
Thank you!