Soru

Zorluk: KolayLogarithmic and Exponential Expressions and Equations

If log4x=32\log_4 x = \frac{3}{2}, what is the value of xx?

  1. A
    66
  2. 88Cevap
  3. C
    1212
  4. D
    6464
  5. E
    8116\frac{81}{16}

Cevap

The correct answer is 88.
To solve the equation log4x=32\log_4 x = \frac{3}{2}, we apply the definition of a logarithm to rewrite it in exponential form: x=43/2x = 4^{3/2}. We then evaluate the exponent by first taking the square root of 44, which is 22, and then cubing it to get 23=82^3 = 8. Thus, the value of xx is 88.

Adım Adım Çözüm

1
Rewrite the logarithmic equation in its equivalent exponential form.
x=43/2x = 4^{3/2}
By definition, a logarithmic equation of the form logba=c\log_b a = c is equivalent to the exponential equation bc=ab^c = a.
2
Evaluate the exponential expression 43/24^{3/2}.
x=8x = 8
The fractional exponent can be simplified by taking the square root of the base first, which is 4=2\sqrt{4} = 2, and then raising the result to the power of the numerator, giving 23=82^3 = 8.

Anahtar Kavram

Converting logarithmic equations to exponential form and evaluating fractional exponents

Alternatif Yöntem

You can solve this by substituting the answer choices back into the equation. For example, testing the value 88 gives log48=log4(23)=3log42\log_4 8 = \log_4 (2^3) = 3 \log_4 2. Since 22 is the square root of 44, log42=12\log_4 2 = \frac{1}{2}. Therefore, 3×12=323 \times \frac{1}{2} = \frac{3}{2}, confirming that 88 is the correct solution.
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