Table of contents
- 0. Functions7h 52m
- Introduction to Functions16m
- Piecewise Functions10m
- Properties of Functions9m
- Common Functions1h 8m
- Transformations5m
- Combining Functions27m
- Exponent rules32m
- Exponential Functions28m
- Logarithmic Functions24m
- Properties of Logarithms34m
- Exponential & Logarithmic Equations35m
- Introduction to Trigonometric Functions38m
- Graphs of Trigonometric Functions44m
- Trigonometric Identities47m
- Inverse Trigonometric Functions48m
- 1. Limits and Continuity2h 2m
- 2. Intro to Derivatives1h 33m
- 3. Techniques of Differentiation3h 18m
- 4. Applications of Derivatives2h 38m
- 5. Graphical Applications of Derivatives6h 2m
- 6. Derivatives of Inverse, Exponential, & Logarithmic Functions2h 37m
- 7. Antiderivatives & Indefinite Integrals1h 26m
2. Intro to Derivatives
Tangent Lines and Derivatives
Problem 65
Textbook Question
A line perpendicular to another line or to a tangent line is often called a normal line. Find an equation of the line perpendicular to the line that is tangent to the following curves at the given point P.
y = 2/x; P(1, 2)
![](/channels/images/assetPage/verifiedSolution.png)
1
Step 1: Find the derivative of the function y = \frac{2}{x} to determine the slope of the tangent line at point P(1, 2). The derivative, y', can be found using the power rule and the fact that \frac{d}{dx}(x^{-1}) = -x^{-2}.
Step 2: Evaluate the derivative at x = 1 to find the slope of the tangent line at point P(1, 2). Substitute x = 1 into the derivative to get the slope of the tangent line.
Step 3: Determine the slope of the line perpendicular to the tangent line. The slope of the normal line is the negative reciprocal of the slope of the tangent line.
Step 4: Use the point-slope form of a line equation, y - y_1 = m(x - x_1), where m is the slope of the normal line and (x_1, y_1) is the point P(1, 2), to write the equation of the normal line.
Step 5: Simplify the equation from Step 4 to get the final equation of the normal line in slope-intercept form, y = mx + b, or any other preferred form.
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