Diketahui f(x)=x³. nilai f'(3) adalah
Nilai f'(3) adalah 27
༺ Penyelesaian ༻
f(x) = x³ ==> f'(x) = 3 . 1 . x^(3-1)
= 3x²
f'(3) = 3(3)²
= 3 . 9
= 27
༺ Pembahasan ༻
Sifat-sifat turunan fungsi:
1. f(x) = k ==> f'(x) = 0
k = konstanta
Contoh soal:
f(x) = 6 ==> f'(x) = 0
2. f(x) = x ==> f'(x) = 1
Contoh soal:
f(x) = 2x ==> f'(x) = 2 . 1 = 2
3. f(x) = a . xⁿ ==> f'(x) = n . a . x^(n – 1)
Contoh soal:
f(x) = 4x² ==> f'(x) = 2 . 4 . x^(2-1)
= 8x
4. h(x) ± g(x) ==> h'(x) ± g'(x)
Contoh soal:
h(x) = 3x
g(x) = 5x
h(x) + g(x) = 3x + 5x
==> h'(x) + g'(x) = 3 . 1 + 5 . 1
= 3 + 5 = 8
5. f(x) = u(x) . v(x)
==> f'(x) = u(x) . v(x) + u(x) . v(x)
Contoh soal:
f(x) = 2x . 4x ==> f'(x) = 2x . 4x + 2x . 4x
= 8x² + 8x²
= 16x²
6. f(x) = u(x)/v(x)
==> f'(x) = [u'(x) . v(x) + u(x) . v'(x)]/[v²(x)]
Contoh soal:
f(x) = 3x – 2/x
f'(x) = (3 (x – 4) + (x ) -3)/(x )²
= 3x – 12 – 3x/x²
= 12/x²
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__ Detail Jawaban:
- Kelas : XI
- Mapel : Matematika
- Materi : Turunan Fungsi Aljabar
- Kode soal : 2
Jawab:
27
Penjelasan dengan langkah-langkah:
f'(x)=3x²
f'(3)=3.3²=3.9=27