What is the value of b2 - 4ac for the following equation? x 2 + 5x + 4 = 0
1 answer:
You might be interested in
Answer:
<em>It will take 9 years for the population to double</em>
Step-by-step explanation:
<u>Exponential Growth </u>
The natural growth of some magnitudes can be modeled by the equation:
Where P is the actual amount of the magnitude, Po is its initial amount, r is the growth rate and t is the time.
The population of a city grows at a rate of r=8% = 0.08 per year. We are required to find when (t) the population will double, or P=2Po.
Substituting in the equation:
Simplifying:
Taking logarithms:
Applying the exponent property of logs:
Solving for t:
Calculating:
It will take 9 years for the population to double
In order to graph the relationship, we will need to write the expression as the equation of a straight line as shown:
d = mt + b
d is the distance covered
t is the time taken
m is the speed
If you are skateboarding at a pace of 30 meters every 5 seconds. your friend is in-line skating at a pace of 9 meters every 2 seconds, this can be written as (5, 30) and (2, 9)
Get the slope of the line:
m = (9-30)/(2-5)
m = -21/-3
m = 7
Substitute m = 7 and the coordinate (2, 9) into the equation y = mt + b
9 = 7(2) + b
9 = 14 + b
b = -5
The required equation to plot will be expressed as y = 7t - 5
Plot the required graph
Learn more here: brainly.com/question/17003809
