2. How would you solve the equation:
x2 = 4
(take the square root of each side!)
x =4
2
x = 4
x = 2 or - 2 *
2
* Remember, the square
root of a positive # has
2 answers! (one + and
one -)
6. Rationalizing the Denominator
You CANNOT leave a radical in the
denominator of a fraction!
(the numerator is OK)
Just multiply the top & bottom of the fraction
by the radical to ârationalizeâ the
denominator.
7. More Examples!
1.
25
3
25
=
3
5 * 3
=
3 * 3
=
5 3
9
=
5 3
3
Canât have a tent in the
basement!
2.
2
11
2
=
11
* 11
22
=
* 11
121
22
=
11
9. More Examples!
3. Solve. 4x -6=42
+6 +6
4x2=48
4
4
x2 = 12
x 2 = ± 12
2
x = ± 4 * 3 = ±2 3
1
5
4. Solve. ( x â 4) 2 = 6
( x â 4) 2 = 30
( x â 4) 2 = ± 30
x â 4 = ± 30
x = 4 ± 30
10. Falling Objects!
âą Use h = -16t2 + h0
Height
of the
object
after it
has
fallen
# of seconds
after the
object is
dropped
Objectâs
initial
height
11. Example
âą The tallest building in
the USA is in
Chicago, Illinois. It is
1450 ft. tall. How
long would it take a
penny to drop from
the top of the building
to the ground?
h = â16t 2 + h0
0 = â16t + 1450
2
â 1450 = â16t
90.625 = t
2
2
90.625 = t 2
t â 9.52 seconds