The problem asks to find a formula for the linear function $f(x)$ with a slope of 9 and a vertical intercept of 0.

In general, the formula for a linear function is given by the equation:

$f(x) = mx + b$

Where:

• $m$ is the slope
• $b$ is the vertical intercept (or y-intercept)

Given:

• Slope $m = 9$
• Vertical intercept $b = 0$

So, the equation becomes:

$f(x) = 9x + 0$

Simplifying:

$f(x) = 9x$

This is the required formula for the linear function.

Would you like further details or clarification on this?

Here are 5 related questions to consider:

1. What is the meaning of the slope in a linear function?
2. How would the graph of $f(x) = 9x$ look like?
3. How would the equation change if the vertical intercept were different from 0?
4. How do you find the slope from two points on a line?
5. What is the significance of the y-intercept in real-world applications?

Tip: When the slope is positive, the line increases as you move from left to right; when negative, it decreases.