Question

A battery with

2
0
%
20%20, percent of its full capacity is connected to a charger. Every minute that passes, an additional
5
%
5%5, percent of its capacity is charged.
Graph the battery's capacity (in
%
%percent charged) as a function of time (in minutes).

Answer 1

Given,

The original percentage of battery = 20 %,

Also, Every minute that passes, an additional 5%,

So, the increment in percentage after x minutes = 5x percentage

Thus, the final battery after x minutes = ( 20 + 5x ) %

Let y represents the total percentage of battery after x minutes,

⇒ y = 20 + 5x

Which is the required function that shows the given situation.

For graphing,

y = 20 + 5x is a line having x-intercept = (-4,0)

And, y-intercept = (0,20)

Also, battery's capacity and time can not be negative,

⇒ x ≥ 0 , y ≥ 0

Answer 2

y = 5x + 20

Start at (0, 20).
Then plot a point at (1, 25).

The line should be going through points (2, 30), (3, 35), (4, 40), (5, 45), etc.

For every time the x number goes up, the y number goes up 5 times for the 5%.