Deriving the quadratic formula – Texas Instruments TITANIUM TI-89 User Manual

Page 743

Advertising
background image

Activities

743

Deriving the Quadratic Formula

Deriving the Quadratic Formula

Deriving the Quadratic Formula

Deriving the Quadratic Formula

This activity shows you how to derive the quadratic formula:

x =

4. Use the

zeros( )

function to compute the

zeros of the first derivative of

c(w)

to find

the minimum value of

c(w)

.

Note:

The maximum length of the pole is

the minimum value of

c(w)

.

5. Compute the exact maximum length of

the pole.

Enter:

c

(

2 ±)

6. Compute the approximate maximum

length of the pole.

Result: Approximately 20.8097 feet.

Note:

Use the auto-paste feature to copy

the result from step 4 to the entry line
inside the parentheses of c( ) and press

8 ¸.

b

b

2

4ac

±

2a

---------------------------------------

Advertising