Answer:
a) domain: (0, ∞)
b) range: (-∞, ∞)
c) increasing everywhere
d) concave downward
Step-by-step explanation:
a) Your knowledge of the log function tells you it is defined for positive arguments. 9x > 0 means x > 0. The domain is all positive real numbers.
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b) Your knowledge of the log function tells you it has output values ranging from -∞ to +∞. The range is all real numbers.
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c) The function is monotonically increasing.
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d) Since the output does not increase as fast as the input (the first derivative is decreasing), the function is concave downward.
