Core Connections Integrated II, 2015
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Core Connections Integrated II, 2015 View details
2. Section 6.2
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Exercise 102 Page 359

Practice makes perfect
a We can show that the given equation is true by considering its left-hand side. Then, we will simplify the expression on the left-hand side and show that it is equal to the expression on right-hand side.
(i-3)^2 = 8-6iTo simplify the expression on the left-hand side, let's start by applying the formula, (a-b)^2=a^2-2ab+b^2. Recall the definition of the imaginary unit, i^2=- 1.
(i-3)^2
i^2-2(i)(3)+3^2
-1-2(i)(3)+3^2
-1-6i+3^2
-1-6i+9
8-6i
Finally, note that the obtained expression is equal to the expression on the right-hand side of the given equation. 8-6i = 8-6i Therefore, the given equation is true.
b Similarly as in Part A, we can show that the given equation is true by considering the left-hand side. Then, we will simplify the expression on the left-hand side and show that it is equal to the expression on right-hand side.
(2i-1)(3i+1) = -7-iTo simplify the expression on the left-hand side, let's start by applying the Distributive Property. Recall the definition of the imaginary unit i, i^2=- 1.
(2i-1)(3i+1)
â–Ľ
Distribute
2i(3i+1)-1(3i+1)
6i^2+2i-1(3i+1)
6i^2+2i-3i-1
6(-1)+2i-3i-1
-6+2i-3i-1
-7-i
Finally, note that the obtained expression is equal to the expression on the right-hand side of the given equation. -7-i = -7-i Therefore, the given equation is true.
c We can show that the given equation is true by considering the left-hand side. Then, we will simplify the expression on the left-hand side and show that it is equal to the expression on right-hand side.
(3-2i)(2i+3) = 13To simplify the expression on the left-hand side, let's start by applying the Distributive Property. Recall the definition of the imaginary unit i, i^2=- 1.
(3-2i)(2i+3)
â–Ľ
Distribute
3(2i+3)-2i(2i+3)
6i+9-2i(2i+3)
6i+9-4i^2-6i
6i+9-4(-1)-6i
6i+9+4-6i
13
Finally, note that the obtained expression is equal to the expression on the right-hand side of the given equation. 13 = 13 Therefore, the given equation is true.