Asksia AI LOGO

Sia

Question
Math
Posted 9 months ago

Consider the following problem:
The horizontal leg a(t)a(t) of a right triangle is increasing at a rate of 8 m/s8 \mathrm{~m} / \mathrm{s} and the vertical leg b(t)b(t) of the triangle is increasing at a rate of 7 m/s7 \mathrm{~m} / \mathrm{s}. At a certain instant t0t_{0}, the horizontal leg is 13 m13 \mathrm{~m} and the vertical leg is 10 m10 \mathrm{~m}. What is the rate of change of the length c(t)c(t) of the hypotenuse at that instant?

Match each expression with its units.
Sign in to unlock the answer
Answer from Sia
Posted 9 months ago
Solution by Steps
step 1
We start by noting the given information: a(t)=13ma(t) = 13 \, \text{m}, b(t)=10mb(t) = 10 \, \text{m}, dadt=8m/s\frac{da}{dt} = 8 \, \text{m/s}, and dbdt=7m/s\frac{db}{dt} = 7 \, \text{m/s}. We need to find dcdt\frac{dc}{dt}, where c(t)c(t) is the hypotenuse of the right triangle
step 2
Using the Pythagorean theorem, we have c(t)=a(t)2+b(t)2c(t) = \sqrt{a(t)^2 + b(t)^2}
step 3
Differentiating both sides with respect to tt, we get ddt[c(t)]=ddt[a(t)2+b(t)2]\frac{d}{dt}[c(t)] = \frac{d}{dt}[\sqrt{a(t)^2 + b(t)^2}]
step 4
Applying the chain rule, we obtain dcdt=12a(t)2+b(t)22a(t)dadt+2b(t)dbdt\frac{dc}{dt} = \frac{1}{2\sqrt{a(t)^2 + b(t)^2}} \cdot 2a(t)\frac{da}{dt} + 2b(t)\frac{db}{dt}
step 5
Simplifying, we get dcdt=a(t)dadt+b(t)dbdta(t)2+b(t)2\frac{dc}{dt} = \frac{a(t)\frac{da}{dt} + b(t)\frac{db}{dt}}{\sqrt{a(t)^2 + b(t)^2}}
step 6
Substituting the given values, we have dcdt=138+107132+102=104+70169+100=174269\frac{dc}{dt} = \frac{13 \cdot 8 + 10 \cdot 7}{\sqrt{13^2 + 10^2}} = \frac{104 + 70}{\sqrt{169 + 100}} = \frac{174}{\sqrt{269}}
step 7
Simplifying further, dcdt=17426910.6m/s\frac{dc}{dt} = \frac{174}{\sqrt{269}} \approx 10.6 \, \text{m/s}
Answer
The rate of change of the length of the hypotenuse is approximately 10.6m/s10.6 \, \text{m/s}.
Key Concept
Rate of change of the hypotenuse in a right triangle
Explanation
The rate of change of the hypotenuse can be found by differentiating the Pythagorean theorem with respect to time and substituting the given rates of change of the legs.

Not the question you are looking for? Ask here!

Enter question by text

Enter question by image

Unlock Smarter Learning with AskSia Super!

Join Super, our all-in-one AI solution that can greatly improve your learning efficiency.

30% higher accuracy than GPT-4o
Entire learning journey support
The most student-friendly features
Study Other Question