Matching heights A stone is thrown with an initial velocity of 32 ft/s from the edge of a bridge that is 48 ft above the ground. The height of this stone above the ground t seconds after it is thrown is f(t) = −16t²+32t+48 . If a second stone is thrown from the ground, then its height above the ground after t seconds is given by g(t) = −16t²+v0t, where v0 is the initial velocity of the second stone. Determine the value of v0 such that both stones reach the same high point.
Ch. 3 - Derivatives
Briggs3rd EditionCalculus: Early TranscendentalsISBN: 9780136847243Not the one you use?Change textbook
Chapter 3, Problem 3.8.8
5–8. Calculate dy/dx using implicit differentiation.
e^y-e^x = C, where C is constant
Verified step by step guidance1
Start by differentiating both sides of the equation with respect to x. The equation is e^y - e^x = C. Since C is a constant, its derivative is 0.
Differentiate e^y with respect to x. Use the chain rule: the derivative of e^y with respect to y is e^y, and then multiply by dy/dx because y is a function of x.
Differentiate e^x with respect to x. The derivative of e^x with respect to x is simply e^x.
Set up the equation from the derivatives: e^y * (dy/dx) - e^x = 0.
Solve for dy/dx by isolating it on one side of the equation: e^y * (dy/dx) = e^x, then divide both sides by e^y to get dy/dx = e^x / e^y.

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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Implicit Differentiation
Implicit differentiation is a technique used to find the derivative of a function when it is not explicitly solved for one variable in terms of another. Instead of isolating y, we differentiate both sides of the equation with respect to x, applying the chain rule when differentiating terms involving y. This method is particularly useful for equations where y cannot be easily expressed as a function of x.
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Finding The Implicit Derivative
Chain Rule
The chain rule is a fundamental principle in calculus that allows us to differentiate composite functions. It states that if a function y is defined as a function of u, which in turn is a function of x, then the derivative of y with respect to x can be found by multiplying the derivative of y with respect to u by the derivative of u with respect to x. This is essential in implicit differentiation when dealing with terms involving y.
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Intro to the Chain Rule
Exponential Functions
Exponential functions are mathematical functions of the form f(x) = e^x, where e is the base of the natural logarithm. These functions have unique properties, such as their derivative being equal to the function itself. In the context of the given equation, understanding how to differentiate e^y and e^x is crucial for applying implicit differentiation correctly and finding dy/dx.
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Exponential Functions
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