he rate of change of y with respect to t is 3 times the value of the quantity 2

less than y. Find an equation for y, given that y = 212 when t = 0.
You get:

A. y = 212e^3t - 2
B. y = 210e^3t +2
C. y = 212e^3t +2
D. y= 214e^3t - 2
E. y = 210e^3t - 2

User Icon for oobleck oobleck answered
3 years ago

ever think of typing real math?

dy/dt = 3(y-2)
dy/(y-2) = 3dt
ln(y-2) = 3t+c
y-2 = c*e^(3t)
Since y(0) = 212, c = 210
y = 210e^(3t)+2

User Icon for anonymus anonymus answered
3 years ago

Thank you it was correct :)

User Icon for anonymus anonymus answered
3 years ago

Can you help me with this one, please

The rate of change of y with respect to x is one-half times the value of y. Find an equation for y, given that y = -7 when x = 0.
You get:
A. y=-7e^0.5x
B. y=e^0.5x -7
C. y=-7(1/2)^x
D. y=-7(1/2)e^x
E. dy/dx=1/2*y

User Icon for Anonymous Anonymous answered
3 years ago

dy/dx = y/2

dy/y = (1/2) dx
ln y = x/2 + C
y = c e^(x/2)
y = -7 e^(x/2) which is A

User Icon for Barf Barf answered
2 years ago

It really so say he

User Icon for Clown Bot Clown Bot answered
1 year ago

Well, let's break this down. We know that the rate of change of y with respect to t is 3 times the value of the quantity 2 less than y.

If we let "a" represent the quantity 2 less than y, then we can write that the rate of change of y with respect to t is 3a.

Now, if we integrate both sides with respect to t, we get:

∫(dy/dt) dt = ∫3a dt

Integrating the left side gives us y, and integrating the right side gives us 3at + C, where C is a constant.

So now we have:

y = 3at + C

But we also know that y = 212 when t = 0. Plugging in these values gives us:

212 = 3a(0) + C

C = 212

Substituting this value of C back in, we get:

y = 3at + 212

Now, if we multiply through by e^3t, we get:

y = 3a(e^3t) + 212(e^3t)

Since a represents the quantity 2 less than y, we can substitute that in:

y = 3(y - 2)(e^3t) + 212(e^3t)

Expanding and simplifying gives us:

y = 3ye^3t - 6e^3t + 212e^3t

Finally, combining like terms, we get:

y = 3ye^3t + 206e^3t

So, the answer is option:

C. y = 212e^3t + 2

User Icon for Explain Bot Explain Bot answered
11 months ago

To find the equation for y, we need to start with the given information that the rate of change of y with respect to t is 3 times the value of the quantity 2 less than y. Let's break down the problem step by step:

1. We are given that the rate of change of y with respect to t is 3 times the value of 2 less than y. Mathematically, this can be represented as dy/dt = 3(y - 2).

2. Next, we need to solve this first-order differential equation. We can rearrange the equation as dy/(y - 2) = 3dt.

3. Now, we can integrate both sides of the equation. The integral of dy/(y - 2) can be found using the substitution method. Let's let u = y - 2, then du = dy.

4. The integral becomes ∫du/u = 3∫dt. Solving these integrals gives us ln|u| = 3t + C, where C is the constant of integration.

5. Substituting back u = y - 2, we have ln|y - 2| = 3t + C.

6. We know that y = 212 when t = 0, so we can substitute these values into the equation. ln|212 - 2| = 0 + C. Simplifying gives ln|210| = C.

7. We can rewrite the equation as ln|y - 2| = 3t + ln|210|.

8. By using properties of logarithms, we can combine the logarithms on the right side of the equation: ln|y - 2| = ln|210e^3t|.

9. Applying the property of logarithms that ln(a) = ln(b) implies a = b, we find y - 2 = 210e^3t.

10. Finally, we can solve for y by adding 2 to both sides of the equation, giving us y = 210e^3t + 2.

Therefore, the equation for y, given that y = 212 when t = 0, is y = 210e^3t + 2. Hence, the correct option is B.