d29e8e910f99467fd071c526d98b7e69.ppt
- Количество слайдов: 18
3. 5 Linear Equations in Three Variables
Do Now §Grab some slides from the front. §Take out your homework and check your answers. The answers are found in the slides. (Note: Answers to the classwork from yesterday are posted online. )
#1
#2
#3
#4 x: number of ounces of Food X y: number of ounces of Food Y C=0. 2 x+0. 3 y Corner Points: (0, 4) (0, 5) (3, 0) (5, 0) (1, 2) Minimum of $0. 60 for (3, 0), so use 3 oz. of Food X.
That’s a Matador!
Coordinate Graph in Three Variables
8 Octants I. x > 0, y > 0, z > 0 V. x > 0, y > 0, z < 0 II. x > 0, y < 0, z > 0 VI. x > 0, y < 0, z < 0 III. x < 0, y < 0, z > 0 VII. x < 0, y < 0, z < 0 IV. x < 0, y > 0, z > 0 VIII. x < 0, y > 0, z < 0
Plot (-2, 3, 2)
Graph 3 x+2 y+4 z=12
Graph 6 x-3 y+9 z=36
Write the Equation of the Plane Given the Intercepts • • ax+by+cz=d form Example: x-intercept 1/2, y-intercept 1, z-intercept -5/2 Points (1/2, 0, 0), (0, 1, 0), (0, 0, -5/2) Now • Divide by d:
Need first coefficient positive and all coefficients as integers, so multiply by 5. Answer:
You Try! Find the equation of the plane with x-intercept of 4, y-intercept of -2, and z-intercept of 4 in standard form. x-2 y+z=4
f(x, y) Write 3 x-12 y+5 z=30 as a function of x and y in function notation. Find f(-2, 2). Isolate “z”. Replace “z” with f(x, y).
Application You are buying tulips, carnations, and a glass vase to make a flower arrangement. The flower shop sells tulips for $. 70 each and carnations for $. 30 each. The glass vase costs $12. Write a model for the total cost of the flower arrangement as a function of the number of tulips and carnations you use. How much would it cost for 10 tulips and 5 carnations? t=number of tulips, c=number of carnations f(t, c)=. 70 t+. 30 c+12 f(10, 5)=. 70(10)+. 30(5)+12=$20. 50
For You! You want to buy an aquarium and stock it with goldfish and angelfish. The pet store sells goldfish for $. 40 each and angelfish for $4 each. The aquarium starter kit costs $65. Write a model for the amount you will spend as a function of the number of goldfish and angelfish you buy. How much do you pay if you buy 6 goldfish and 10 angelfish?
d29e8e910f99467fd071c526d98b7e69.ppt