Mathematics

Mathematics

Problem

Determine the range of the function h(x)=log⁡7(x+5)+2h(x)=\log_{7}(x+5)+2. a) y≥2y\ge 2 b) All real numbers c) y>2y>2 d) y≤2y\le 2
Intuitive explanation

This is a logarithmic transformation problem. The key insight is that the range of a logarithm depends on what values the argument (the input to the log) can take. Since log⁡7\log_7 can output any real number as its argument ranges over all positive values, you need to figure out what x+5x+5 can be, then see what log⁡7(x+5)\log_7(x+5) produces, and finally account for the vertical shift of +2+2. The domain restriction on xx will constrain the argument, which in turn determines the range.

Intuitive explanation

This is a logarithmic transformation problem. The key insight is that the range of a logarithm depends on what values the argument (the input to the log) can take. Since log⁡7\log_7 can output any real number as its argument ranges over all positive values, you need to figure out what x+5x+5 can be, then see what log⁡7(x+5)\log_7(x+5) produces, and finally account for the vertical shift of +2+2. The domain restriction on xx will constrain the argument, which in turn determines the range.

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