Do Now from 1.1a…

Do Now from 1.1a… • Solve algebraically and graphically…

More interesting info in Section 1.1 - grapher failure, hidden behavior, more problem solving…

First problem of the day… 3 Find all x-intercepts of y = 2x – 5 Solving algebraically??? (there are no x-intercepts) Solving graphically??? This is an example of grapher failure – when a graphical model misrepresents the phenomena being studied

Try another problem: 3 2 Solve graphically: x – 1.1x – 65.4x + 229.5 = 0 x = –9, 5, 5.1 This is an example of hidden behavior – when an inaccurate viewing window obscures details of a graph

Now, on to some basic problem solving… The engineers at an auto manufacturer pay students $0.08 per mile plus $25 per day to road test their new vehicles. 1. Derive an algebraic model for the students’ pay. p = 0.08x + 25 (where p = students’ pay, and x = miles driven)

Now, on to some basic problem solving… The engineers at an auto manufacturer pay students $0.08 per mile plus $25 per day to road test their new vehicles. 2. How much did the auto manufacturer pay Sally to drive 440 miles in one day? $60.20 3. John earned $93 test-driving a new car in one day. How far did he drive? 850 miles

Now, on to some basic problem solving… A math student’s grade is determined by weights, with homework counting 20% and quizzes/tests counting 80%. • Derive an algebraic model for the student’s grade, given that • homework and quizzes/tests are graded by points. Total HW pts. Total Q/T pts. g = 0.2 + 0.8 Poss. HW pts. Poss. Q/T pts.

Now, on to some basic problem solving… A math student’s grade is determined by weights, with homework counting 20% and quizzes/tests counting 80%. 2. What is Wolfgang’s grade if he has earned 26 out of a possible 28 homework points, quiz grades of 22/25 and 13/15, and a test grade of 41/50? Grade = 86.127%

Now, on to some basic problem solving… A math student’s grade is determined by weights, with homework counting 20% and quizzes/tests counting 80%. 3. If Jan has perfect homework scores and quiz scores of 20/25 and 14/15, what does she need to earn on the upcoming 50-point test in order to have an overall 90% grade average? At least 44.75 points

Now, on to some basic problem solving… At an air show, a pilot drops a smoke bomb to signal the start of the show. Ignoring air resistance, an object in free fall will fall d feet in t seconds, where d and t are related by: 1. How long will it take the bomb to fall 180 feet? Approximately 3.354 sec

Now, on to some basic problem solving… At an air show, a pilot drops a smoke bomb to signal the start of the show. Ignoring air resistance, an object in free fall will fall d feet in t seconds, where d and t are related by: 2. If the bomb is in free fall for 12.5 seconds after it is dropped, how high was the airplane when the bomb was dropped? Altitude: 2500 feet

Now, on to some basic problem solving… Solve the given equation graphically by converting it to an equivalent equation with 0 on the right-hand side and then finding the x-intercepts. 1. 2. Homework: p. 77-79 21, 23, 25-27 all, 39-47 odd

Do Now from 1.1a…

Do Now from 1.1a…

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