Answer:
66
Step-by-step explanation:
Find other side:
116 + x = 180
-116 -116
------------------
x = 64
Find missing triangle angle:
50 + 64 + x = 180
114 + x = 180
-114 -114
-------------------
x = 66
Hope this helped.
Answer:
i dont understand
Step-by-step explanation:
Answer:
-10
Step-by-step explanation:
50 ÷ (-5)
First ignore the brackets and the negative sign.
Then divide 50 by 5 to get 10
Then return the negative sign so the answer is; -10
Answer:
The car gets 35 miles per gallons.
Step-by-step explanation:
I assume each path
is oriented positively/counterclockwise.
(a) Parameterize
by
![\begin{cases} x(t) = 4\cos(t) \\ y(t) = 4\sin(t)\end{cases} \implies \begin{cases} x'(t) = -4\sin(t) \\ y'(t) = 4\cos(t) \end{cases}](https://tex.z-dn.net/?f=%5Cbegin%7Bcases%7D%20x%28t%29%20%3D%204%5Ccos%28t%29%20%5C%5C%20y%28t%29%20%3D%204%5Csin%28t%29%5Cend%7Bcases%7D%20%5Cimplies%20%5Cbegin%7Bcases%7D%20x%27%28t%29%20%3D%20-4%5Csin%28t%29%20%5C%5C%20y%27%28t%29%20%3D%204%5Ccos%28t%29%20%5Cend%7Bcases%7D)
with
. Then the line element is
![ds = \sqrt{x'(t)^2 + y'(t)^2} \, dt = \sqrt{16(\sin^2(t)+\cos^2(t))} \, dt = 4\,dt](https://tex.z-dn.net/?f=ds%20%3D%20%5Csqrt%7Bx%27%28t%29%5E2%20%2B%20y%27%28t%29%5E2%7D%20%5C%2C%20dt%20%3D%20%5Csqrt%7B16%28%5Csin%5E2%28t%29%2B%5Ccos%5E2%28t%29%29%7D%20%5C%2C%20dt%20%3D%204%5C%2Cdt)
and the integral reduces to
![\displaystyle \int_C xy^4 \, ds = \int_{-\pi/2}^{\pi/2} (4\cos(t)) (4\sin(t))^4 (4\,dt) = 4^6 \int_{-\pi/2}^{\pi/2} \cos(t) \sin^4(t) \, dt](https://tex.z-dn.net/?f=%5Cdisplaystyle%20%5Cint_C%20xy%5E4%20%5C%2C%20ds%20%3D%20%5Cint_%7B-%5Cpi%2F2%7D%5E%7B%5Cpi%2F2%7D%20%284%5Ccos%28t%29%29%20%284%5Csin%28t%29%29%5E4%20%284%5C%2Cdt%29%20%3D%204%5E6%20%5Cint_%7B-%5Cpi%2F2%7D%5E%7B%5Cpi%2F2%7D%20%5Ccos%28t%29%20%5Csin%5E4%28t%29%20%5C%2C%20dt)
The integrand is symmetric about
, so
![\displaystyle 4^6 \int_{-\pi/2}^{\pi/2} \cos(t) \sin^4(t) \, dt = 2^{13} \int_0^{\pi/2} \cos(t) \sin^4(t) \,dt](https://tex.z-dn.net/?f=%5Cdisplaystyle%204%5E6%20%5Cint_%7B-%5Cpi%2F2%7D%5E%7B%5Cpi%2F2%7D%20%5Ccos%28t%29%20%5Csin%5E4%28t%29%20%5C%2C%20dt%20%3D%202%5E%7B13%7D%20%5Cint_0%5E%7B%5Cpi%2F2%7D%20%5Ccos%28t%29%20%5Csin%5E4%28t%29%20%5C%2Cdt)
Substitute
and
. Then we get
![\displaystyle 2^{13} \int_0^{\pi/2} \cos(t) \sin^4(t) \, dt = 2^{13} \int_0^1 u^4 \, du = \frac{2^{13}}5 (1^5 - 0^5) = \boxed{\frac{8192}5}](https://tex.z-dn.net/?f=%5Cdisplaystyle%202%5E%7B13%7D%20%5Cint_0%5E%7B%5Cpi%2F2%7D%20%5Ccos%28t%29%20%5Csin%5E4%28t%29%20%5C%2C%20dt%20%3D%202%5E%7B13%7D%20%5Cint_0%5E1%20u%5E4%20%5C%2C%20du%20%3D%20%5Cfrac%7B2%5E%7B13%7D%7D5%20%281%5E5%20-%200%5E5%29%20%3D%20%5Cboxed%7B%5Cfrac%7B8192%7D5%7D)
(b) Parameterize
by
![\begin{cases} x(t) = 2(1-t) + 5t = 3t - 2 \\ y(t) = 0(1-t) + 4t = 4t \end{cases} \implies \begin{cases} x'(t) = 3 \\ y'(t) = 4 \end{cases}](https://tex.z-dn.net/?f=%5Cbegin%7Bcases%7D%20x%28t%29%20%3D%202%281-t%29%20%2B%205t%20%3D%203t%20-%202%20%5C%5C%20y%28t%29%20%3D%200%281-t%29%20%2B%204t%20%3D%204t%20%5Cend%7Bcases%7D%20%5Cimplies%20%5Cbegin%7Bcases%7D%20x%27%28t%29%20%3D%203%20%5C%5C%20y%27%28t%29%20%3D%204%20%5Cend%7Bcases%7D)
with
. Then
![ds = \sqrt{3^2+4^2} \, dt = 5\,dt](https://tex.z-dn.net/?f=ds%20%3D%20%5Csqrt%7B3%5E2%2B4%5E2%7D%20%5C%2C%20dt%20%3D%205%5C%2Cdt)
and
![\displaystyle \int_C x e^y \, ds = \int_0^1 (3t-2) e^{4t} (5\,dt) = 5 \int_0^1 (3t - 2) e^{4t} \, dt](https://tex.z-dn.net/?f=%5Cdisplaystyle%20%5Cint_C%20x%20e%5Ey%20%5C%2C%20ds%20%3D%20%5Cint_0%5E1%20%283t-2%29%20e%5E%7B4t%7D%20%285%5C%2Cdt%29%20%3D%205%20%5Cint_0%5E1%20%283t%20-%202%29%20e%5E%7B4t%7D%20%5C%2C%20dt)
Integrate by parts with
![u = 3t-2 \implies du = 3\,dt \\\\ dv = e^{4t} \, dt \implies v = \frac14 e^{4t}](https://tex.z-dn.net/?f=u%20%3D%203t-2%20%5Cimplies%20du%20%3D%203%5C%2Cdt%20%5C%5C%5C%5C%20dv%20%3D%20e%5E%7B4t%7D%20%5C%2C%20dt%20%5Cimplies%20v%20%3D%20%5Cfrac14%20e%5E%7B4t%7D)
![\displaystyle \int u\,dv = uv - \int v\,du](https://tex.z-dn.net/?f=%5Cdisplaystyle%20%5Cint%20u%5C%2Cdv%20%3D%20uv%20-%20%5Cint%20v%5C%2Cdu)
![\implies \displaystyle 5 \int_0^1 (3t-2) e^{4t} \,dt = \frac54 (3t-2) e^{4t} \bigg|_{t=0}^{t=1} - \frac{15}4 \int_0^1 e^{4t} \,dt \\\\ ~~~~~~~~ = \frac54 (e^4 + 2) - \frac{15}{16} e^{4t} \bigg|_{t=0}^{t=1} \\\\ ~~~~~~~~ = \frac54 (e^4 + 2) - \frac{15}{16} (e^4 - 1) = \boxed{\frac{5e^4 + 55}{16}}](https://tex.z-dn.net/?f=%5Cimplies%20%5Cdisplaystyle%205%20%5Cint_0%5E1%20%283t-2%29%20e%5E%7B4t%7D%20%5C%2Cdt%20%3D%20%5Cfrac54%20%283t-2%29%20e%5E%7B4t%7D%20%5Cbigg%7C_%7Bt%3D0%7D%5E%7Bt%3D1%7D%20-%20%5Cfrac%7B15%7D4%20%5Cint_0%5E1%20e%5E%7B4t%7D%20%5C%2Cdt%20%5C%5C%5C%5C%20~~~~~~~~%20%3D%20%5Cfrac54%20%28e%5E4%20%2B%202%29%20-%20%5Cfrac%7B15%7D%7B16%7D%20e%5E%7B4t%7D%20%5Cbigg%7C_%7Bt%3D0%7D%5E%7Bt%3D1%7D%20%5C%5C%5C%5C%20~~~~~~~~%20%3D%20%5Cfrac54%20%28e%5E4%20%2B%202%29%20-%20%5Cfrac%7B15%7D%7B16%7D%20%28e%5E4%20-%201%29%20%3D%20%5Cboxed%7B%5Cfrac%7B5e%5E4%20%2B%2055%7D%7B16%7D%7D)
(c) Parameterize
by
![\begin{cases} x(t) = 3(1-t)+t = -2t+3 \\ y(t) = (1-t)+2t = t+1 \\ z(t) = 2(1-t)+5t = 3t+2 \end{cases} \implies \begin{cases} x'(t) = -2 \\ y'(t) = 1 \\ z'(t) = 3 \end{cases}](https://tex.z-dn.net/?f=%5Cbegin%7Bcases%7D%20x%28t%29%20%3D%203%281-t%29%2Bt%20%3D%20-2t%2B3%20%5C%5C%20y%28t%29%20%3D%20%281-t%29%2B2t%20%3D%20t%2B1%20%5C%5C%20z%28t%29%20%3D%202%281-t%29%2B5t%20%3D%203t%2B2%20%5Cend%7Bcases%7D%20%5Cimplies%20%5Cbegin%7Bcases%7D%20x%27%28t%29%20%3D%20-2%20%5C%5C%20y%27%28t%29%20%3D%201%20%5C%5C%20z%27%28t%29%20%3D%203%20%5Cend%7Bcases%7D)
with
. Then
![ds = \sqrt{(-2)^2 + 1^2 + 3^2} \, dt = \sqrt{14} \, dt](https://tex.z-dn.net/?f=ds%20%3D%20%5Csqrt%7B%28-2%29%5E2%20%2B%201%5E2%20%2B%203%5E2%7D%20%5C%2C%20dt%20%3D%20%5Csqrt%7B14%7D%20%5C%2C%20dt)
and
![\displaystyle \int_C y^2 z \, ds = \int_0^1 (t+1)^2 (3t+2) \left(\sqrt{14}\,ds\right) \\\\ ~~~~~~~~ = \sqrt{14} \int_0^1 \left(3t^3 + 8t^2 + 7t + 2\right) \, dt \\\\ ~~~~~~~~ = \sqrt{14} \left(\frac34 t^4 + \frac83 t^3 + \frac72 t^2 + 2t\right) \bigg|_{t=0}^{t=1} \\\\ ~~~~~~~~ = \sqrt{14} \left(\frac34 + \frac83 + \frac72 + 2\right) = \boxed{\frac{107\sqrt{14}}{12}}](https://tex.z-dn.net/?f=%5Cdisplaystyle%20%5Cint_C%20y%5E2%20z%20%5C%2C%20ds%20%3D%20%5Cint_0%5E1%20%28t%2B1%29%5E2%20%283t%2B2%29%20%5Cleft%28%5Csqrt%7B14%7D%5C%2Cds%5Cright%29%20%5C%5C%5C%5C%20~~~~~~~~%20%3D%20%5Csqrt%7B14%7D%20%5Cint_0%5E1%20%5Cleft%283t%5E3%20%2B%208t%5E2%20%2B%207t%20%2B%202%5Cright%29%20%5C%2C%20dt%20%5C%5C%5C%5C%20~~~~~~~~%20%3D%20%5Csqrt%7B14%7D%20%5Cleft%28%5Cfrac34%20t%5E4%20%2B%20%5Cfrac83%20t%5E3%20%2B%20%5Cfrac72%20t%5E2%20%2B%202t%5Cright%29%20%5Cbigg%7C_%7Bt%3D0%7D%5E%7Bt%3D1%7D%20%5C%5C%5C%5C%20~~~~~~~~%20%3D%20%5Csqrt%7B14%7D%20%5Cleft%28%5Cfrac34%20%2B%20%5Cfrac83%20%2B%20%5Cfrac72%20%2B%202%5Cright%29%20%3D%20%5Cboxed%7B%5Cfrac%7B107%5Csqrt%7B14%7D%7D%7B12%7D%7D)