JEE MAIN - Mathematics (2024 - 8th April Morning Shift - No. 14)
Explanation
First, let's start by substituting $$y = (8)^x$$ in the given equation. By substituting, the equation $$8^{2x} - 16 \cdot 8^x + 48 = 0$$ will be transformed into
$$ y^2 - 16y + 48 = 0 $$
Now, we have a quadratic equation in $$y$$. To find the roots of this quadratic equation, we can use the quadratic formula:
$$ y = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} $$
In this case, $$a = 1$$, $$b = -16$$, and $$c = 48$$. Substituting these values into the formula, we get:
$$ y = \frac{16 \pm \sqrt{256 - 192}}{2} $$
$$ y = \frac{16 \pm \sqrt{64}}{2} $$
$$ y = \frac{16 \pm 8}{2} $$
Solving for the two possible values of $$y$$, we have:
$$ y = \frac{16 + 8}{2} = 12 $$
$$ y = \frac{16 - 8}{2} = 4 $$
Now, recall that we substituted $$y = (8)^x$$. So, we need to solve for $$x$$ when $$y = 12$$ and $$y = 4$$:
$$ 8^x = 12 $$
$$ x = \log_8(12) $$
$$ 8^x = 4 $$
$$ x = \log_8(4) $$
Therefore, the solutions for $$x$$ are $$\log_8(12)$$ and $$\log_8(4)$$. The sum of these solutions is:
$$ \log_8(12) + \log_8(4) $$
Using the logarithmic property that $$\log_b(m) + \log_b(n) = \log_b(m \cdot n)$$, we get:
$$ \log_8(12) + \log_8(4) = \log_8(12 \cdot 4) $$
$$ = \log_8(48) $$
Now, we note that:
$$ 48 = 8 \cdot 6 $$
Thus,
$$ \log_8(48) = \log_8(8 \cdot 6) = \log_8(8) + \log_8(6) = 1 + \log_8(6) $$
Therefore, the sum of all the solutions of the equation is:
Option A $$1 + \log_8(6)$$.
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