HP 39g+ Graphing manual Solve the unknown variable Plot the equation

Solve the unknown variable

Plot the equation

4.Enter the values for the known variables.

2 7 7 8

1 6 6 7

1 0 0

H I N T If the Decimal Mark setting in the Modes input form

( MODES) is set to Comma, use instead of .

5.Solve for the unknown variable (A).

Therefore, the acceleration needed to increase the speed of a car from 16.67 m/sec (60 kph) to 27.78 m/sec

(100 kph) in a distance of 100 m is approximately 2.47 m/s2.

Because the variable A in the equation is linear we know that we need not look for any other solutions.

The Plot view shows one graph for each side of the selected equation. You can choose any of the variables to be the independent variable.

The current equation is V2 = U2 + 2AD .

One of these is Y = V2 , with V = 27.78 , that is,

Y= 771.7284 . This graph will be a horizontal line. The other graph will be Y = U2 + 2AD , with

U = 16.67 and D = 100 , that is,

Y = 200A + 277.8889 . This graph is also a line. The desired solution is the value of A where these two lines intersect.

Solve aplet 7-3