Find the domain X where the inequality exists
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Find the domain X where the inequality exists
Let's solve the inequality .
The expression can be rewritten as using the power property, which states .
Thus, the inequality transforms to:
Since implies when and , the inequality becomes:
Simplifying:
Add 12 to both sides:
Divide both sides by 2:
For both sides of the logarithmic inequality to be defined, we need to ensure:
Solving involves factorization:
This quadratic inequality gives critical points at and . Testing intervals around these points, the inequality holds when or . Considering the logarithmic condition , we narrow it to .
The combined condition from steps 2 and 3 yield:
Therefore, the solution to the inequality is .
\( \log_75-\log_72= \)
Because logarithms are only defined for positive arguments! If x²+2x-12 becomes negative, log₃(x²+2x-12) doesn't exist. You must ensure both sides are valid before solving.
Factor the quadratic: . This is positive when both factors have the same sign, giving you x < -4 or x > 3. Combined with x > 0, you get x > 3.
Because the base 3 > 1, the logarithm function is increasing. This means if A < B and both are positive, then log₃(A) < log₃(B). The inequality direction is preserved!
You only found the domain restriction, not the full solution! The domain gives you x > 3, but solving the actual inequality gives you x > 6. The final answer combines both: x > 6.
Yes! The same method works for any base b > 1. Just remember that for 0 < b < 1, the inequality direction flips when you remove the logarithms.
Pick a test value like x = 7. Check: and . Wait, that's wrong! Let me recalculate: and . Since 3.54 > 3.23, we need x = 8: and . Now 3.79 > 3.58, confirming x > 6 works!
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