Complete the table of values for f(x)=4(2)x and g(x)=5x+6.

x f(x) g(x)
1
2
3
4
Both f(x) and g(x) grow as x gets larger and larger. Which function eventually exceeds the other?

1 answer

To complete the table for the functions \( f(x) = 4(2^x) \) and \( g(x) = 5x + 6 \), we will calculate the values for each function at \( x = 1, 2, 3, \) and \( 4 \).

Calculations

For \( f(x) = 4(2^x) \):

  • \( f(1) = 4(2^1) = 4 \times 2 = 8 \)
  • \( f(2) = 4(2^2) = 4 \times 4 = 16 \)
  • \( f(3) = 4(2^3) = 4 \times 8 = 32 \)
  • \( f(4) = 4(2^4) = 4 \times 16 = 64 \)

For \( g(x) = 5x + 6 \):

  • \( g(1) = 5(1) + 6 = 5 + 6 = 11 \)
  • \( g(2) = 5(2) + 6 = 10 + 6 = 16 \)
  • \( g(3) = 5(3) + 6 = 15 + 6 = 21 \)
  • \( g(4) = 5(4) + 6 = 20 + 6 = 26 \)

Completed Table

| x | f(x) | g(x) | |---|------|------| | 1 | 8 | 11 | | 2 | 16 | 16 | | 3 | 32 | 21 | | 4 | 64 | 26 |

Analysis of Growth

As \( x \) gets larger, we see:

  • At \( x = 1 \), \( f(1) = 8 \) and \( g(1) = 11 \) ( \( g(1) > f(1) \) )
  • At \( x = 2 \), \( f(2) = 16 \) and \( g(2) = 16 \) ( \( g(2) = f(2) \) )
  • At \( x = 3 \), \( f(3) = 32 \) and \( g(3) = 21 \) ( \( f(3) > g(3) \) )
  • At \( x = 4 \), \( f(4) = 64 \) and \( g(4) = 26 \) ( \( f(4) > g(4) \) )

Conclusion

Although both functions grow as \( x \) increases, \( g(x) \) is greater than \( f(x) \) for \( x = 1 \) and equal for \( x = 2 \). However, \( f(x) \) exceeds \( g(x) \) starting from \( x = 3 \) and grows much faster thereafter due to its exponential growth compared to the linear growth of \( g(x) \).

Therefore, the function \( f(x) \) eventually exceeds \( g(x) \) starting from \( x = 3 \).