All categories

3 years ago

1. Suppose xy = 20, where x and y are functions of t. What

Mathematics

1 answer:

Marizza181 [45]3 years ago

6 0

Answer:

(c) 1.6

Step-by-step explanation:

Given, xy = 20 and both x, y are functions of t.

So,

⇒ $\frac{d(xy)}{dt} = x\frac{dy}{dt} + y\frac{dx}{dt}$

now, when x = 4, y will be 5 as xy = 20.

by subtituting the values in above equation, we get;

⇒ $\frac{d(20)}{dt} = 4(-2) + 5\frac{dx}{dt}$

⇒ $0 = -8 + 5\frac{dx}{dt}$

⇒ $\frac{dx}{dt} = \frac{8}{5}$

⇒ $\frac{dx}{dt} = 1.6$

You might be interested in

Question 7

CaHeK987 [17]

Answer:

6.6

Step-by-step explanation:

The way to do this is to find the tax as a decimal. Worry about the 100 later.

54 * x = 3.56

Divide by 54

x = 3.56/54

x = .06593

Now use the 100

0.06592 * 100 = 6.593

But you want it rounded to the 1/10

So you should get 6.6 %

6 0

3 years ago

A scientist raised $32,506 for his project. He later found out that he would need $57,500 to completely pay for it. How much mor

hammer [34]

We need to subtract: the scientist needed 57,500 dollars, but already had 32,506, so we need to find what's left: 57,500 - 32,506 = 24,992 dollars

Your answer is A. Hope that helps! :)

3 0

3 years ago

Read 2 more answers

Age If you add Natalie's age and Fred's age, the result is 43. If you add Fred's age to 4 times

Len [333]

Let’s take fred age as x and Natalie’s age as y.
So,
A/Q
X + Y = 43. Let it be eqution 1
and
X + 4Y = 79. Let it be equation 2

Combining equation 1 and 2, we get

( X + Y) + 3Y = 79
43 + 3Y = 79
3Y = 36
Y = 12

Now, evaluating the value of Y in equation 1 we get,

X + 12 = 43
X = 31

Therefore, Fred is 31years old and Natalie is 12 years old.

8 0

3 years ago

Duke pays $111.60 for his yearly movie pass plus $4.00 for popcorn for each movie.Tenneshia pays $16.40 for a ticket to every mo

melamori03 [73]

Answer:

After 9 movies they will have paid the same amount

Step-by-step explanation:

We must write an equation for Duke's expenses and an equation to represent Tennessee's expenses.

<u>For Duke expenses we have:</u>

A fixed expense of $ 111.60 per year

A variable expense of $ 4.00 for each movie.

The equation that represents the expenses is a linear equation like the one shown below

$C = 111.60 + 4.00x$

Where C represents the cost and x the number of movies.

<u>For Tennessee expenses we have:</u>

A variable expense of $ 16.40 for each film.

The equation that represents the expenses is a linear equation like the one shown below

$C = 16.40x$

Where C represents the cost and x the number of movies.

To know after how many movies have paid the same amount, we equate both equations and solve the variable x

$111.60 +4.00x=16.40x\\\\16.40x - 4x = 111.60\\\\12.40x =111.60\\\\x =\frac{111.60}{12.40}\\\\x =9$

After 9 movies they will have paid the same amount

5 0

3 years ago

A function f is described by f(x)=A*exp(kx)+B, where A, B and k are constants. Given f(0)=1, f(1)=2, and that the horizontal asy

s2008m [1.1K]

Answer:

k = ln (6/5)

Step-by-step explanation:

for

f(x)=A*exp(kx)+B

since f(0)=1, f(1)=2

f(0)= A*exp(k*0)+B = A+B = 1

f(1) = A*exp(k*1)+B = A*e^k + B = 2

assuming k>0 , the horizontal asymptote H of f(x) is

H= limit f(x) , when x→ (-∞)

when x→ (-∞) , limit f(x) = limit (A*exp(kx)+B) = A* limit [exp(kx)]+B* limit = A*0 + B = B

since

H= B = (-4)

then

A+B = 1 → A=1-B = 1 -(-4) = 5

then

A*e^k + B = 2

5*e^k + (-4) = 2

k = ln (6/5) ,

then our assumption is right and k = ln (6/5)

8 0

3 years ago