Page 11 - MATEMATIKA PEMINATAN
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2. f (x) = Sin x
f (x) = Cos x
1
′
= lim +ℎ −
ℎ→0 ℎ
cos( +ℎ)− cos
= lim
ℎ→0 ℎ
+ℎ+ ( +ℎ+ )
−2 sin( ) sin
= lim 2 2
ℎ→0 ℎ
2 +ℎ ℎ
−2 sin( ) sin
= lim 2 2
ℎ→0 ℎ
ℎ
2 +ℎ
2
= lim − 2 ( ) .
ℎ→0 2 ℎ
2 +ℎ 1
= lim −2 sin ( )
ℎ→0 2 2
2 +ℎ
= lim −2 sin ( )
ℎ→0 2
2 +0
= − ( )
2
2 Jadi y = Cos x
= −
2
= − = - sin x
