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Bab Limit
Matematika SMA Kelas XI

Lim ((2 cos 2x) / (cos x - sin x))
x→π/4

= lim. ((2(cos² x - sin² x)) / (cos x - sin x))
...x→π/4

= lim ((2 (cos x + sin x) (cos x - sin x))/(cos x - sin x)
...x→π/4

= lim (2 (cos x + sin x))
...x→π/4

= 2 (cos π/4 + sin π/4)
= 2 (1/2 √2 + 1/2 √2)
= 2 x √2
= 2√2