Core Connections Integrated II, 2015
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Core Connections Integrated II, 2015 View details
2. Section 5.2
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Exercise 91 Page 292

Practice makes perfect
a We want to calculate the value of the given expression. To do this, let's start from simplifying the expression under the radical symbol. While solving, remember the order of operations.
- 6+sqrt(6^2-(4)(1)(- 40))/2 * 1
- 6+sqrt(36-(4)(1)(- 40))/2 * 1
- 6+sqrt(36-(4)(- 40))/2
- 6+sqrt(36+160)/2
â–Ľ
Simplify
- 6+sqrt(196)/2
- 6+14/2
8/2
4
Notice that this solution is one of the answers of Part A in the previous exercise. For further information about this correlation, please refer to the extra information at the end of Part D.
b We want to calculate the value of the given expression. To do this, let's start from simplifying the expression under the radical symbol. While solving, remember the order of operations.
- 6-sqrt(6^2-(4)(1)(- 40))/2 * 1
- 6-sqrt(36-(4)(1)(- 40))/2 * 1
- 6-sqrt(36-(4)(- 40))/2
- 6-sqrt(36+160)/2
â–Ľ
Simplify
- 6-sqrt(196)/2
- 6-14/2
- 20/2
- 10
Notice that this solution is one of the answers of Part A in the previous exercise. For further information about this correlation, please refer to the extra information at the end of Part D.
c We want to calculate the value of the given expression. To do this, let's start from simplifying the expression under the radical symbol. While solving, remember about the order of operations.
- 13-sqrt(13^2-(4)(2)(- 24))/2 * 2
- 13-sqrt(169-(4)(2)(- 24))/2 * 2
- 13-sqrt(169-(8)(- 24))/4
- 13-sqrt(169+192)/4
â–Ľ
Simplify
- 13-sqrt(361)/4
- 13-19/4
- 32/4
- 8
Notice that this solution is one of the answers of Part B in the previous exercise. For further information about this correlation, please refer to the extra information at the end of Part D.
d We want to calculate the value of the given expression. To do this, let's start from simplifying the expression under the radical symbol. While solving, remember the order of operations.
- 13+sqrt(13^2-(4)(2)(- 24))/2 * 2
- 13+sqrt(169-(4)(2)(- 24))/2 * 2
- 13+sqrt(169-(8)(- 24))/4
- 13+sqrt(169+192)/4
â–Ľ
Simplify
- 13+sqrt(361)/4
- 13+19/4
6/4
3/2

Notice that this solution is one of the answers of Part B in the previous exercise.

The correlation explained

To explain the correlation between the solutions of current exercise and the previous exercise, let's recall the given formulas and corresponding equations.

Formula Equation
- 6+sqrt(6^2-(4)( 1)( - 40))/2 * 1 1x^2+ 6x - 40=0
- 6-sqrt(6^2-(4)( 1)( - 40))/2 * 1 1x^2+ 6x - 40=0
- 13-sqrt(13^2-(4)( 2)( - 24))/2 * 2 2x^2+ 13x - 24=0
- 13+sqrt(13^2-(4)( 2)( - 24))/2 * 2 2x^2+ 13x - 24=0

Looking at the table, we can see that a pattern occurs. x=- b±sqrt(b^2-4 a c)/2 a In the above formula a, b, and c correspond with the values of a quadratic equation written in the standard form, ax^2+ bx+ c=0. This formula is called the Quadratic Formula, and it can be used to find solutions to quadratic equations.