lim x mendekati π/4 (1-sin 2x) / (cos 2x)

= 1- 2 sin x cos x / 1- 2 [tex] sin^{2} x[/tex]
= [1- 2 . [tex] \frac{1}{2} \sqrt{2} . \frac{1}{2} \sqrt{2} [/tex] ]/ [1- 2 . [tex] \frac{1}{2} \sqrt{2} . \frac{1}{2} \sqrt{2} [/tex] ]
= 1