2.) Suatu fungsi dinyatakan oleh . Jika
, maka tentukanlah nilai
!
1.) Jika suatu fungsi dinyatakan oleh , maka tentukanlah nilai f(2) dan f(-4)
» Langkah²
1⟩. f(x) = x³ – 2x² + 3x – 7
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f(2) = 2³ – 2(2²) + 3(2) – 7
f(2) = 8 – 2(4) + 6 – 7
f(2) = 8 – 8 + 6 – 7
f(2) = 0 + 6 – 7
f(2) = 6 – 7
f(2) = – 1
f(-4) = (-4)³ – 2(-4)² + 3(-4) – 7
f(-4) = (-64) – 2(16) + (-12) – 7
f(-4) = (-64) – 32 – 12 – 7
f(-4) = (-96) – 12 – 7
f(-4) = (-108) – 7
f(-4) = (-115)
2⟩. f(x) = 5x – 3
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f(a) = 32
5a – 3 = 32
5a = 32 + 3
5a = 35
a = 35 : 5
a = 7
FUNGSI KOMPOSISI
1.
f(x) = x³ -2x² + 3x -7
f(2) = 2³ -2(2)² + 3(2) -7
f(2) = 8 -2(4) + 6 -7
f(2) = 8 -8 -1
f(2) = -1
f(-4) = (-4)³ -2(-4)² + 3(-4) -7
f(-4) = -64 -2(16) -12 -7
f(-4) = -64 -32 -19
f(-4) = -115
2.
f(x) = 5x -3
f(a) = 32
5a -3 = 32
5a = 35