Question

Two different businesses model their profits over 15 years, where x is the year, f(x) is the profits of a garden shop, and g(x) is the profits of a construction materials business. Use the data to determine which function is exponential, and use the table to justify your answer.
1. f(x) is exponential; an exponential function increases more slowly than a linear function.
2. f(x) is exponential; f(x) increased more overall than g(x).
3. g(x) is exponential; g(x) has a higher starting value and higher ending value.
4. g(x) is exponential; an exponential function increases faster than a linear function.

Answer 1

Hi there!

$\large\boxed{\text{Choice 4}}$

We can look at each function, f(x) and g(x), to determine which is exponential.

Use slope formula: m = y2-y1/x2-x1

f(x) starts off with a slope at about $1800/year, but becomes about $1100/year.

g(x) starts off with a slope of about $1500/year, but becomes about $1874/year.

Thus, g(x) is exponential, because g(x)'s slope is increasing across the interval.