University:
Missouri State University
Course:
MTH 103 | Intermediate Algebra
Academic year:

2019
Views:

386

Pages:

2
Author:

Braiden Lam

Name: Key Pd: Date: 3.4 Real Life Applications Example: The percent y (in decimal form) of battery power remaining x hours after you turn on a laptop. computer is y = - 0.2x + 1 a) Graph the equation +0.9 b) Interpret the x- and y- intercepts 20.8 x-intercept: 5 hours will use the entire battery (1002) 0.6 0.5 04 y-Intercept: 100% of battery left still when no time has passed 0.2 0.1 07 c) After how many hours is the battery power at 75%? X ト 1 2 3 4 5 6 7 8 9 10 75 = - 0.2x + 1 - 0.25 = - 0.2x 0.25 = x 1.25 hours - 0.25/- 0.2 (- 1/4) / (- 1/5) - 1/4, - 5/1 = 5/2 = 1.25 #hours battery used You Try: The amount y (in gallons) of gasoline x hours is y = - 2x + 12 a) Graph the equation b) Interpret the x- and y-intercepts x-intercept: lo hours to use all gas in tank (ega) y-intercept: 12 gals gas in tank when Omidirven 11 10 #aal gos remaining 0765432 0 c) After how many hours are there 5 gallons left? X 5 = - 2x + 12 - 7 = - 2x 7/2 = x 15 3.Shours 1 2 3 4 5 6 7 8 9 #hours driven Example: The graph relates temperatures y (in degrees Fahrenheit) to temperatures x (in degrees Celsius) a) Find the slope and y-intercept m = 9/2 b = 32 86c - 32 3x0 = 54 30 = 18/10 = 9/5 b) Write the equation of the line y = 9/5 * x + 32 (y = mx + b) c) What is the mean temperature of Earth in degrees Fahrenheit? mean = 15°C y - F y = 9/5 * x + 32 y = 4/5 * (15) + 32 y = 9(3) + 32 x - c م y = 27 + 32 y = 59 59°F You Try: The graph shows the height y (in feet) of a flag x seconds after you start raising it up a flagpole. a) Find and interpret the slope m = 2/2 up 3ft every 2 seconds (t * e ^ (- 7/3))/(z + 0) b) Write an equation of the line y = 3/2 * x + 3 c) What is the height of the flag after 9 seconds? X y = 3/2 * (9) + 3 y = 27/2 + 3 11 = 13, 5 + 3 y = 1Lo, 5 (16.5ft high) y 15 12- 9 6 3) Fay 90 75 60 32) 15 -30-10 7 (30, 86) (0, D 10 20 30 40 x Mean Temperature: 15°C (2, 6) 2 3 4 Height of flag (0, -1 y-intercept 1 5 x #seconds