Using intercepts

Question

Jaime bought a jar of 50 vitamins. His two children each take one vitamin each day. The number of vitamins left in the jar after X days is represented by the function f(x)=50-2x. Graph the function and explain what each intercept represents

Answer 1

f(x) = 50 - 2x

Replace f(x) with y

x represents number of days

y represents number of vitamins left

 

y = 50-2x

 

x   |   y

---|-----

0  |  50

25 |  0    0 =50-2x, 2x=50, x=25

 

Plot the points

(0, 50) y-intercept

(25, 0) x-intercept

 

The y-intercept means that at zero

days - New bottle, none taken yet -

we had 50 vitamins.

 

The x-intercept means that after 25

days we will have zero vitamins left.

 

Note:  You may want to number your

x and y axis in multiples of 10...

10, 20, 30, 40, 50

instead of 1, 2, 3,..., 50