Solve for:
4^x+4^(1/x)=18
just by inspection, x=2
As well:
x = 1/2
To solve the equation 4^x + 4^(1/x) = 18, we can follow these steps:
Step 1: Let's rewrite the equation using a common base. Since both terms have base 4, we can rewrite 18 as 4^(log4(18)), using the logarithm base-change rule.
Therefore, our equation becomes:
4^x + 4^(1/x) = 4^(log4(18))
Step 2: Now, we can equate the exponents of the same base. This means:
x = log4(18)
Step 3: To solve for x, we need to evaluate log4(18). We can rewrite the logarithmic equation as an exponential equation:
4^x = 18
Step 4: We can now solve for x by taking the logarithm of both sides of the equation using the base 4 logarithm:
log4(4^x) = log4(18)
x = log4(18)
Step 5: We can use a calculator to evaluate log4(18). The base 4 logarithm is equivalent to the common logarithm divided by log4. Therefore:
x ≈ log(18) / log(4)
Using a calculator, we find:
x ≈ 1.8019
So, the approximate solution to the equation is x ≈ 1.8019.