Since
, we can rewrite the integral as

Now there is no ambiguity about the definition of f(t), because in each integral we are integrating a single part of its piecewise definition:

Both integrals are quite immediate: you only need to use the power rule

to get
![\displaystyle \int_0^11-3t^2\;dt = \left[t-t^3\right]_0^1,\quad \int_1^4 2t\; dt = \left[t^2\right]_1^4](https://tex.z-dn.net/?f=%5Cdisplaystyle%20%5Cint_0%5E11-3t%5E2%5C%3Bdt%20%3D%20%5Cleft%5Bt-t%5E3%5Cright%5D_0%5E1%2C%5Cquad%20%5Cint_1%5E4%202t%5C%3B%20dt%20%3D%20%5Cleft%5Bt%5E2%5Cright%5D_1%5E4)
Now we only need to evaluate the antiderivatives:
![\left[t-t^3\right]_0^1 = 1-1^3=0,\quad \left[t^2\right]_1^4 = 4^2-1^2=15](https://tex.z-dn.net/?f=%5Cleft%5Bt-t%5E3%5Cright%5D_0%5E1%20%3D%201-1%5E3%3D0%2C%5Cquad%20%5Cleft%5Bt%5E2%5Cright%5D_1%5E4%20%3D%204%5E2-1%5E2%3D15)
So, the final answer is 15.
Answer:
D, B, C, A
Step-by-step explanation:
Solve the equations by combining like terms, isolating the variable, and dividing the equation by the coefficient of the variable.
Doing this, the first equation should be 2, the second equation should be -2, the third equation should be -1, and the last equation should be -6.
Then, we can order them.
Before we solve for anything, let's remember what our formula is.
The circumference of a circle is 2PiR (2 x Pi x R).
Our radius is 157.64.
Pi is 3.14 (estimated).
Let's plug our numbers into the formula.
Circumference = 2 x 3.14 x 157.64.
2 x 3.14 = 6.28
6.28 x 157.64 = 989.979 (990 if estimated).
Your circumference is:
989.979 ft^2.
I hope this helps!