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2. Overview. Section 6.7 in the textbook:Solving Quadratic word problemsApplying the Pythagorean Theorem. 3. Solving Quadratic Word Problems. . Solving Quadratic Word Problems. Object is to extract a quadratic equation from the word problemSolve by factoringTakes practice. 4. Solving Quadratic Word Problems (Example).
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1. Quadratic Equations and Problem Solving MATH 018
Combined Algebra
S. Rook
2. 2 Overview Section 6.7 in the textbook:
Solving Quadratic word problems
Applying the Pythagorean Theorem
3. 3 Solving Quadratic Word Problems
4. Solving Quadratic Word Problems Object is to extract a quadratic equation from the word problem
Solve by factoring
Takes practice 4
5. Solving Quadratic Word Problems (Example) Ex 1: Set up a quadratic equation and solve:
a) The difference of the square of a number and the number itself is thirty
b) The sum of four times the square of a number and eight times the number itself is negative three
c) Two consecutive odd integers whose product is 63 5
6. Applying the Pythagorean Theorem
7. Applying the Pythagorean Theorem Pythagorean Theorem: given a right triangle with legs a & b and hypotenuse c, the following relationship exists: a2 + b2 = c2
It does not matter which of the legs is a and which is b
The hypotenuse, c, is the longest side AND is ALWAYS opposite the 90°-angle
When solving problems with right triangles, it is often helpful to draw a picture 7
8. Applying the Pythagorean Theorem (Continued) Bear in mind the domain of the problem (i.e. what the problem is addressing)
Even though some solutions of an equation may be mathematically correct, they may not make sense in the context of the problem
What is the domain of the Pythagorean Theorem?
What do you know sign-wise about the domain? 8
9. Applying the Pythagorean Theorem (Example) Ex 2: A 10 foot ladder is leaning on a building which is perpendicular to the ground where the top of the ladder (vertically) extends two feet more than across the ground (horizontally). Set up an equation and find how many feet the ladder extends off the ground (vertically) 9
10. Applying the Pythagorean Theorem (Example) Ex 3: One leg of a right triangle is 4 millimeters longer than the smaller leg and the hypotenuse is 8 millimeters longer than the smaller leg. Find the lengths of the sides of this triangle 10
11. 11 Summary After studying these slides, you should know how to do the following:
Solve quadratic word problems
Solve problems involving the Pythagorean Theorem
Additional Practice
See the list of suggested problems for 6.7
Next lesson
Simplifying Rational Expressions (Section 7.1)