# Differentiating polynomials example | Derivative rules | AP Calculus AB | Khan Academy | Summary and Q&A

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July 20, 2016
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Differentiating polynomials example | Derivative rules | AP Calculus AB | Khan Academy

## TL;DR

This video explains how to find the derivative of a polynomial expression and how it can be used to determine the slope of a tangent line.

## Questions & Answers

### Q: What is the purpose of taking the derivative of a function?

Taking the derivative of a function allows us to find the rate of change or slope of the function at any given point. It helps us understand how the function behaves and how it is changing.

### Q: How do you find the derivative of a polynomial expression?

To find the derivative of a polynomial expression, we use the power rule. We bring the exponent down as a coefficient, then subtract 1 from the exponent. We apply this rule to each term in the expression and add or subtract the derivatives accordingly.

### Q: How can the derivative expression help determine tangent line slopes?

The derivative expression represents the slope of the tangent line at any point on the graph. By plugging in the x-coordinate of a specific point into the derivative expression, we can calculate the slope of the tangent line at that point.

### Q: How can the slope of a tangent line be interpreted?

The slope of a tangent line represents the rate of change or steepness of the function at a specific point. A higher slope indicates a steeper curve, while a lower slope indicates a less steep or flatter curve.

## Summary & Key Takeaways

• The video demonstrates how to take the derivative of a polynomial expression using the power rule and derivative properties.

• It explains the notation for derivatives and how to calculate the derivatives of each term in the expression.

• The video shows how the derivative expression can be used to find the slope of a tangent line at a specific point on the graph.