Flashback 9-11-12 The lead of a screw is the distance that the screw advances in a straight line when the screw is turned 1 complete turn. If a screw is 2  inches long and has a lead of   inch, how many complete turns would get it all the way into a piece of wood? A.   5 B. 10 C. 15 D. 20 E. 25 If xy = 144, x + y = 30, and x > y, what is the value of x – y ? F.   4 G.   6 H. 18 J. 22 K. 24

6 out of 5 people have difficulty with fractions. Joke of the day 6 out of 5 people have difficulty with fractions.

Solving Absolute Value Inequalities For < inequalities: Separate the value after the inequality into positive and negative values. Remove the absolute value bars and place the expression between the negative and positive values. Solve.

Example |x – 4| < 8 -8 < x – 4 < 8

Solving > absolute value inequalities Separate the value after the inequality into positive and negative values. Then put expression inside absolute value < the negative value. Put the expression inside the absolute value > the positive value.

Example | 3x – 2| > 5 3x – 2 ≤ -5 or 3x – 2 ≥ 5

What about quadratics? Solve the inequality as if it is an equation, and find the zeroes. Use the graph to see where the equation has positive values for >, negative values for <

Example X2 – x – 12 > 0 Solve X2 – x – 12 = 0 Look at the graph. Graph is positive from - 3 to -∞ and from 4 to ∞

Example 2 X2 + 2x + 2 < 0

Cubics! x3 + 2x2 – 1 ≥ 0

Practical application!!! Projectile motion s = -16t2 + v0 + s0 V0 is initial velocity, S0 is initial position p. 63 initial velocity of 288 ft/sec, launched from ground

p. 63 initial velocity of 288 ft/sec, launched from ground When will s= 1152 ft? When will s be at least 1152 ft?

Homework  P. 64 Ex. 1-15 odd, 27, 29, 33, 34

Exit Slip Solve x2 – 4x < 1 graphically.