Answer:
B. [tex]\displaystyle -\frac{1}{3}[/tex]
General Formulas and Concepts:
Pre-Algebra
Order of Operations: BPEMDAS
- Brackets
- Parenthesis
- Exponents
- Multiplication
- Division
- Addition
- Subtraction
Equality Properties
- Multiplication Property of Equality
- Division Property of Equality
- Addition Property of Equality
- Subtraction Property of Equality
Algebra I
- Terms/Coefficients
- Exponential Rule [Rewrite]: [tex]\displaystyle b^{-m} = \frac{1}{b^m}[/tex]
- Exponential Rule [Root Rewrite]: [tex]\displaystyle \sqrt[n]{x} = x^{\frac{1}{n}}[/tex]
Calculus
Derivatives
Derivative Notation
Derivative of a constant is 0
The definition of a derivative is the slope of the tangent line
Basic Power Rule:
- f(x) = cxⁿ
- f’(x) = c·nxⁿ⁻¹
Implicit Differentiation
Step-by-step explanation:
Step 1: Define
[tex]\displaystyle \sqrt{x} + \sqrt{y} = 2[/tex]
[tex]\displaystyle (\frac{9}{4}, \frac{1}{4})[/tex]
Step 2: Differentiate
Implicit Differentiation
- [Function] Rewrite [Exponential Rule - Root Rewrite]: [tex]\displaystyle x^{\frac{1}{2}} + y^{\frac{1}{2}} = 2[/tex]
- [Function] Basic Power Rule: [tex]\displaystyle \frac{1}{2}x^{\frac{1}{2} - 1} + \frac{1}{2}y^{\frac{1}{2} - 1}\frac{dy}{dx} = 0[/tex]
- [Derivative] Simplify: [tex]\displaystyle \frac{1}{2}x^{\frac{-1}{2}} + \frac{1}{2}y^{\frac{-1}{2}}\frac{dy}{dx} = 0[/tex]
- [Derivative] Rewrite [Exponential Rule - Rewrite]: [tex]\displaystyle \frac{1}{2x^{\frac{1}{2}}} + \frac{1}{2y^{\frac{1}{2}}}\frac{dy}{dx} = 0[/tex]
- [Derivative] Isolate [tex]\displaystyle \frac{dy}{dx}[/tex] term [Subtraction Property of Equality]: [tex]\displaystyle \frac{1}{2y^{\frac{1}{2}}}\frac{dy}{dx} = -\frac{1}{2x^{\frac{1}{2}}}[/tex]
- [Derivative] Isolate [tex]\displaystyle \frac{dy}{dx}[/tex] [Multiplication Property of Equality]: [tex]\displaystyle \frac{dy}{dx} = -\frac{2y^{\frac{1}{2}}}{2x^{\frac{1}{2}}}[/tex]
- [Derivative] Simplify: [tex]\displaystyle \frac{dy}{dx} = -\frac{y^{\frac{1}{2}}}{x^{\frac{1}{2}}}[/tex]
Step 3: Evaluate
Find slope of tangent line
- Substitute in point [Derivative]: [tex]\displaystyle \frac{dy}{dx} \bigg| \limit_{(\frac{9}{4}, \frac{1}{4})} = -\frac{(\frac{1}{4})^{\frac{1}{2}}}{(\frac{9}{4})^{\frac{1}{2}}}[/tex]
- [Slope] Exponents: [tex]\displaystyle \frac{dy}{dx} \bigg| \limit_{(\frac{9}{4}, \frac{1}{4})} = -\frac{\frac{1}{2}}{\frac{3}{2}}[/tex]
- [Slope] Simplify: [tex]\displaystyle \frac{dy}{dx} \bigg| \limit_{(\frac{9}{4}, \frac{1}{4})} = -\frac{1}{3}[/tex]
Topic: AP Calculus AB/BC (Calculus I/II)
Unit: Differentiation - Implicit Differentiation
Book: College Calculus 10e