Which of the following statements is true about the function f(x)=5x+5

a.
The function is an increasing function.

b.
The function is a decreasing function.

c.
The function is a constant function.

d.
It is not a function

1 answer

The given function is \( f(x) = 5x + 5 \).

To determine whether the function is increasing, decreasing, constant, or not a function, we can analyze its characteristics:

  • Increasing Function: A function is increasing if its derivative is positive for all \( x \). The derivative of \( f(x) \) is \( f'(x) = 5 \), which is positive for all \( x \). Therefore, the function is increasing.

  • Decreasing Function: Since the derivative is positive, the function is not decreasing.

  • Constant Function: A constant function has a derivative of zero. Since \( f'(x) = 5 \), it is not a constant function.

  • Not a Function: The expression \( f(x) = 5x + 5 \) clearly defines a function of \( x \).

Based on this analysis, the true statement is:

a. The function is an increasing function.