Answer:
x + y = 13
98x + 115y = z
Step-by-step explanation:
Let x represent the time spent taking class in Westside community college
Let y represent the time spent taking class in Pinewood community college
Let z represent the combined total amount paid for the class fees.
The total combined time for the two school is given as:
x + y = 13.
For the combined total amount; we multiply the price for each school with the time spent on the school and sum them together.
Westside: ![98 * x = 98x](https://tex.z-dn.net/?f=98%20%2A%20x%20%3D%2098x)
Pinewood: ![115 * y = 115y](https://tex.z-dn.net/?f=115%20%2A%20y%20%3D%20115y)
The combined total amount represented as z is given as:
z = 98x + 115y
Answer:
Equation of tangent plane to given parametric equation is:
![\frac{\sqrt{3}}{2}x-\frac{1}{2}y+z=\frac{\pi}{3}](https://tex.z-dn.net/?f=%5Cfrac%7B%5Csqrt%7B3%7D%7D%7B2%7Dx-%5Cfrac%7B1%7D%7B2%7Dy%2Bz%3D%5Cfrac%7B%5Cpi%7D%7B3%7D)
Step-by-step explanation:
Given equation
---(1)
Normal vector tangent to plane is:
![\hat{n} = \hat{r_{u}} \times \hat{r_{v}}\\r_{u}=\frac{\partial r}{\partial u}\\r_{v}=\frac{\partial r}{\partial v}](https://tex.z-dn.net/?f=%5Chat%7Bn%7D%20%3D%20%5Chat%7Br_%7Bu%7D%7D%20%5Ctimes%20%5Chat%7Br_%7Bv%7D%7D%5C%5Cr_%7Bu%7D%3D%5Cfrac%7B%5Cpartial%20r%7D%7B%5Cpartial%20u%7D%5C%5Cr_%7Bv%7D%3D%5Cfrac%7B%5Cpartial%20r%7D%7B%5Cpartial%20v%7D)
![\frac{\partial r}{\partial u} =cos(v)\hat{i}+sin(v)\hat{j}\\\frac{\partial r}{\partial v}=-usin(v)\hat{i}+u cos(v)\hat{j}+\hat{k}](https://tex.z-dn.net/?f=%5Cfrac%7B%5Cpartial%20r%7D%7B%5Cpartial%20u%7D%20%3Dcos%28v%29%5Chat%7Bi%7D%2Bsin%28v%29%5Chat%7Bj%7D%5C%5C%5Cfrac%7B%5Cpartial%20r%7D%7B%5Cpartial%20v%7D%3D-usin%28v%29%5Chat%7Bi%7D%2Bu%20cos%28v%29%5Chat%7Bj%7D%2B%5Chat%7Bk%7D)
Normal vector tangent to plane is given by:
![r_{u} \times r_{v} =det\left[\begin{array}{ccc}\hat{i}&\hat{j}&\hat{k}\\cos(v)&sin(v)&0\\-usin(v)&ucos(v)&1\end{array}\right]](https://tex.z-dn.net/?f=r_%7Bu%7D%20%5Ctimes%20r_%7Bv%7D%20%3Ddet%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D%5Chat%7Bi%7D%26%5Chat%7Bj%7D%26%5Chat%7Bk%7D%5C%5Ccos%28v%29%26sin%28v%29%260%5C%5C-usin%28v%29%26ucos%28v%29%261%5Cend%7Barray%7D%5Cright%5D)
Expanding with first row
![\hat{n} = \hat{i} \begin{vmatrix} sin(v)&0\\ucos(v) &1\end{vmatrix}- \hat{j} \begin{vmatrix} cos(v)&0\\-usin(v) &1\end{vmatrix}+\hat{k} \begin{vmatrix} cos(v)&sin(v)\\-usin(v) &ucos(v)\end{vmatrix}\\\hat{n}=sin(v)\hat{i}-cos(v)\hat{j}+u(cos^{2}v+sin^{2}v)\hat{k}\\\hat{n}=sin(v)\hat{i}-cos(v)\hat{j}+u\hat{k}\\](https://tex.z-dn.net/?f=%5Chat%7Bn%7D%20%3D%20%5Chat%7Bi%7D%20%5Cbegin%7Bvmatrix%7D%20sin%28v%29%260%5C%5Cucos%28v%29%20%261%5Cend%7Bvmatrix%7D-%20%5Chat%7Bj%7D%20%5Cbegin%7Bvmatrix%7D%20cos%28v%29%260%5C%5C-usin%28v%29%20%261%5Cend%7Bvmatrix%7D%2B%5Chat%7Bk%7D%20%5Cbegin%7Bvmatrix%7D%20cos%28v%29%26sin%28v%29%5C%5C-usin%28v%29%20%26ucos%28v%29%5Cend%7Bvmatrix%7D%5C%5C%5Chat%7Bn%7D%3Dsin%28v%29%5Chat%7Bi%7D-cos%28v%29%5Chat%7Bj%7D%2Bu%28cos%5E%7B2%7Dv%2Bsin%5E%7B2%7Dv%29%5Chat%7Bk%7D%5C%5C%5Chat%7Bn%7D%3Dsin%28v%29%5Chat%7Bi%7D-cos%28v%29%5Chat%7Bj%7D%2Bu%5Chat%7Bk%7D%5C%5C)
at u=5, v =π/3
---(2)
at u=5, v =π/3 (1) becomes,
![r(5, \frac{\pi}{3})=5 cos (\frac{\pi}{3})\hat{i}+5sin (\frac{\pi}{3})\hat{j}+\frac{\pi}{3}\hat{k}](https://tex.z-dn.net/?f=r%285%2C%20%5Cfrac%7B%5Cpi%7D%7B3%7D%29%3D5%20cos%20%28%5Cfrac%7B%5Cpi%7D%7B3%7D%29%5Chat%7Bi%7D%2B5sin%20%28%5Cfrac%7B%5Cpi%7D%7B3%7D%29%5Chat%7Bj%7D%2B%5Cfrac%7B%5Cpi%7D%7B3%7D%5Chat%7Bk%7D)
![r(5, \frac{\pi}{3})=5(\frac{1}{2})\hat{i}+5 (\frac{\sqrt{3}}{2})\hat{j}+\frac{\pi}{3}\hat{k}](https://tex.z-dn.net/?f=r%285%2C%20%5Cfrac%7B%5Cpi%7D%7B3%7D%29%3D5%28%5Cfrac%7B1%7D%7B2%7D%29%5Chat%7Bi%7D%2B5%20%28%5Cfrac%7B%5Csqrt%7B3%7D%7D%7B2%7D%29%5Chat%7Bj%7D%2B%5Cfrac%7B%5Cpi%7D%7B3%7D%5Chat%7Bk%7D)
![r(5, \frac{\pi}{3})=\frac{5}{2}\hat{i}+(\frac{5\sqrt{3}}{2})\hat{j}+\frac{\pi}{3}\hat{k}](https://tex.z-dn.net/?f=r%285%2C%20%5Cfrac%7B%5Cpi%7D%7B3%7D%29%3D%5Cfrac%7B5%7D%7B2%7D%5Chat%7Bi%7D%2B%28%5Cfrac%7B5%5Csqrt%7B3%7D%7D%7B2%7D%29%5Chat%7Bj%7D%2B%5Cfrac%7B%5Cpi%7D%7B3%7D%5Chat%7Bk%7D)
From above eq coordinates of r₀ can be found as:
![r_{o}=(\frac{5}{2},\frac{5\sqrt{3}}{2},\frac{\pi}{3})](https://tex.z-dn.net/?f=r_%7Bo%7D%3D%28%5Cfrac%7B5%7D%7B2%7D%2C%5Cfrac%7B5%5Csqrt%7B3%7D%7D%7B2%7D%2C%5Cfrac%7B%5Cpi%7D%7B3%7D%29)
From (2) coordinates of normal vector can be found as
Equation of tangent line can be found as:
![(\hat{r}-\hat{r_{o}}).\hat{n}=0\\((x-\frac{5}{2})\hat{i}+(y-\frac{5\sqrt{3}}{2})\hat{j}+(z-\frac{\pi}{3})\hat{k})(\frac{\sqrt{3} }{2}\hat{i}-\frac{1}{2}\hat{j}+\hat{k})=0\\\frac{\sqrt{3}}{2}x-\frac{5\sqrt{3}}{4}-\frac{1}{2}y+\frac{5\sqrt{3}}{4}+z-\frac{\pi}{3}=0\\\frac{\sqrt{3}}{2}x-\frac{1}{2}y+z=\frac{\pi}{3}](https://tex.z-dn.net/?f=%28%5Chat%7Br%7D-%5Chat%7Br_%7Bo%7D%7D%29.%5Chat%7Bn%7D%3D0%5C%5C%28%28x-%5Cfrac%7B5%7D%7B2%7D%29%5Chat%7Bi%7D%2B%28y-%5Cfrac%7B5%5Csqrt%7B3%7D%7D%7B2%7D%29%5Chat%7Bj%7D%2B%28z-%5Cfrac%7B%5Cpi%7D%7B3%7D%29%5Chat%7Bk%7D%29%28%5Cfrac%7B%5Csqrt%7B3%7D%20%7D%7B2%7D%5Chat%7Bi%7D-%5Cfrac%7B1%7D%7B2%7D%5Chat%7Bj%7D%2B%5Chat%7Bk%7D%29%3D0%5C%5C%5Cfrac%7B%5Csqrt%7B3%7D%7D%7B2%7Dx-%5Cfrac%7B5%5Csqrt%7B3%7D%7D%7B4%7D-%5Cfrac%7B1%7D%7B2%7Dy%2B%5Cfrac%7B5%5Csqrt%7B3%7D%7D%7B4%7D%2Bz-%5Cfrac%7B%5Cpi%7D%7B3%7D%3D0%5C%5C%5Cfrac%7B%5Csqrt%7B3%7D%7D%7B2%7Dx-%5Cfrac%7B1%7D%7B2%7Dy%2Bz%3D%5Cfrac%7B%5Cpi%7D%7B3%7D)
Tristan can make 5 fruit baskets with no fruit left over. 9 x 5 = 45 and 4 x 5 = 20
9 apples and 4 pears will go in each fruit basket.