B.rolling a die I hope this helped
Answer with Step-by-step explanation:
We are given that
![r(t)=< t^2,\frac{2}{3}t^3,t >](https://tex.z-dn.net/?f=r%28t%29%3D%3C%20t%5E2%2C%5Cfrac%7B2%7D%7B3%7Dt%5E3%2Ct%20%3E)
We have to find T,N and B at the given point t > (1,
,1)
![r'(t)=](https://tex.z-dn.net/?f=r%27%28t%29%3D%3C2t%2C2t%5E2%2C1%3E)
![\mid r'(t) \mid=\sqrt{(2t)^2+(2t^2)^2+1}=\sqrt{(2t^2+1)^2}=2t^2+1](https://tex.z-dn.net/?f=%5Cmid%20r%27%28t%29%20%5Cmid%3D%5Csqrt%7B%282t%29%5E2%2B%282t%5E2%29%5E2%2B1%7D%3D%5Csqrt%7B%282t%5E2%2B1%29%5E2%7D%3D2t%5E2%2B1)
![T(t)=\frac{r'(t)}{\mid r'(t)\mid}=\frac{}{2t^2+1}](https://tex.z-dn.net/?f=T%28t%29%3D%5Cfrac%7Br%27%28t%29%7D%7B%5Cmid%20r%27%28t%29%5Cmid%7D%3D%5Cfrac%7B%3C2t%2C2t%5E2%2C1%3E%7D%7B2t%5E2%2B1%7D)
Now, substitute t=1
![T(1)=\frac{}{2+1}=\frac{1}{3}](https://tex.z-dn.net/?f=T%281%29%3D%5Cfrac%7B%3C2%2C2%2C1%3E%7D%7B2%2B1%7D%3D%5Cfrac%7B1%7D%7B3%7D%3C2%2C2%2C1%3E)
![T'(t)=\frac{-4t}{(2t^2+1)^2} +\frac{1}{2t^2+1}](https://tex.z-dn.net/?f=T%27%28t%29%3D%5Cfrac%7B-4t%7D%7B%282t%5E2%2B1%29%5E2%7D%20%3C2t%2C2t%5E2%2C1%3E%2B%5Cfrac%7B1%7D%7B2t%5E2%2B1%7D%3C2%2C4t%2C0%3E)
![T'(1)=-\frac{4}{9}+\frac{1}{3}](https://tex.z-dn.net/?f=T%27%281%29%3D-%5Cfrac%7B4%7D%7B9%7D%3C2%2C2%2C1%3E%2B%5Cfrac%7B1%7D%7B3%7D%20%3C2%2C4%2C0%3E)
![T'(1)=\frac{1}{9}=](https://tex.z-dn.net/?f=T%27%281%29%3D%5Cfrac%7B1%7D%7B9%7D%3C-8%2B6%2C-8%2B12%2C-4%2B0%3E%3D%3C%5Cfrac%7B-2%7D%7B9%7D%2C%5Cfrac%7B4%7D%7B9%7D%2C%5Cfrac%7B-4%7D%7B9%7D%20%3E)
![\mid T'(1)\mid=\sqrt{(\frac{-2}{9})^2+(\frac{4}{9})^2+(\frac{-4}{9})^2}=\sqrt{\frac{36}{81}}=\frac{2}{3}](https://tex.z-dn.net/?f=%5Cmid%20T%27%281%29%5Cmid%3D%5Csqrt%7B%28%5Cfrac%7B-2%7D%7B9%7D%29%5E2%2B%28%5Cfrac%7B4%7D%7B9%7D%29%5E2%2B%28%5Cfrac%7B-4%7D%7B9%7D%29%5E2%7D%3D%5Csqrt%7B%5Cfrac%7B36%7D%7B81%7D%7D%3D%5Cfrac%7B2%7D%7B3%7D)
![N(1)=\frac{T'(1)}{\mid T'(1)\mid}](https://tex.z-dn.net/?f=N%281%29%3D%5Cfrac%7BT%27%281%29%7D%7B%5Cmid%20T%27%281%29%5Cmid%7D)
![N(1)=\frac{}{\frac{2}{3}}=](https://tex.z-dn.net/?f=N%281%29%3D%5Cfrac%7B%3C%5Cfrac%7B-2%7D%7B9%7D%2C%5Cfrac%7B4%7D%7B9%7D%2C%5Cfrac%7B-4%7D%7B9%7D%3E%7D%7B%5Cfrac%7B2%7D%7B3%7D%7D%3D%3C%5Cfrac%7B-1%7D%7B3%7D%2C%5Cfrac%7B2%7D%7B3%7D%2C%5Cfrac%7B-2%7D%7B3%7D%3E)
![N(1)=](https://tex.z-dn.net/?f=N%281%29%3D%3C%5Cfrac%7B-1%7D%7B3%7D%2C%5Cfrac%7B2%7D%7B3%7D%2C%5Cfrac%7B-2%7D%7B3%7D%3E)
![B(1)=T(1)\times N(1)](https://tex.z-dn.net/?f=B%281%29%3DT%281%29%5Ctimes%20N%281%29)
![B(1)=\begin{vmatrix}i&j&k\\\frac{2}{3}&\frac{2}{3}&\frac{1}{3}\\\frac{-1}{3}&\frac{2}{3}&\frac{-2}{3}\end{vmatrix}](https://tex.z-dn.net/?f=B%281%29%3D%5Cbegin%7Bvmatrix%7Di%26j%26k%5C%5C%5Cfrac%7B2%7D%7B3%7D%26%5Cfrac%7B2%7D%7B3%7D%26%5Cfrac%7B1%7D%7B3%7D%5C%5C%5Cfrac%7B-1%7D%7B3%7D%26%5Cfrac%7B2%7D%7B3%7D%26%5Cfrac%7B-2%7D%7B3%7D%5Cend%7Bvmatrix%7D)
![B(1)=i(\frac{-4}{9}-\frac{2}{9})-j(\frac{-4}{9}+\frac{1}{3})+k(\frac{4}{9}+\frac{2}{9})](https://tex.z-dn.net/?f=B%281%29%3Di%28%5Cfrac%7B-4%7D%7B9%7D-%5Cfrac%7B2%7D%7B9%7D%29-j%28%5Cfrac%7B-4%7D%7B9%7D%2B%5Cfrac%7B1%7D%7B3%7D%29%2Bk%28%5Cfrac%7B4%7D%7B9%7D%2B%5Cfrac%7B2%7D%7B9%7D%29)
![B(1)=-\frac{2}{3}i+\frac{1}{3}j+\frac{2}{3}k](https://tex.z-dn.net/?f=B%281%29%3D-%5Cfrac%7B2%7D%7B3%7Di%2B%5Cfrac%7B1%7D%7B3%7Dj%2B%5Cfrac%7B2%7D%7B3%7Dk)
![B(1)=\frac{1}{3}](https://tex.z-dn.net/?f=B%281%29%3D%5Cfrac%7B1%7D%7B3%7D%3C-2%2C1%2C2%3E)
The answer to the question
If Jana has to walk 2 blocks north to get to Kyle's home, then 3 blocks south to get to school, this means that she has just retraced the 2 blocks she walked to get to Kyle's home.
So the school is just 1 block south of Jana's home.