Matematika

Pertanyaan

tentukan turunan dari fungsi f(x)=√x pada nilai x=4. Menggunakan rumus

F'(a)= Lim f(a+h)-f(a) / h
h→0

2 Jawaban

  • Langsung aja y

    f(x) = √x
    f(x) = x^½

    f'(x) = ½x^(½-1)
    f'(x) = ½x^-½
    f'(x) = ½ / x^½

    f'(4) = ½ / 4^½
    f'(4) = ½ / 2
    f'(4) = ¼

    Semoga berguna +_+
  • f(x) = x^(1/2)
    f'(x) = lim(a→0) [f(x+a) - f(x)]/a
    lim(a→0) [(x + a)^(1/2) - x^(1/2)]/a
    = lim(a→0) {[(x + a)^(1/2) - x^(1/2)].[(x + a)^(1/2) + x^(1/2)]}/{a.[(x + a)^(1/2) + x^(1/2)]}
    = lim(a→0) [(x + a) - x]/a.[(x + a)^(1/2) + x^(1/2)]
    = lim(a→0) a/{a.[(x + a)^(1/2) + x^(1/2)]}
    = lim(a→0) 1/[(x + a)^(1/2) + x^(1/2)]
    = 1/[x^(1/2) + x^(1/2)]
    = 1/[2x^(1/2)]
    f'(4) = 1/[2.4^(1/2)] = 1/(2.2) = 1/4

    semoga membantu! :)

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