McGraw Hill Integrated II, 2012
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McGraw Hill Integrated II, 2012 View details
2. Complex Numbers
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Exercise 4 Page 182

Recall that sqrt(- 1)=i.

- 72sqrt(3)

Practice makes perfect
We can simplify the given expression by combining like terms. Recall the definition of the imaginary unit i. sqrt(-1)=iLet's begin by rewriting the roots that have a negative radicand as imaginary numbers.
3sqrt(- 24) * 2sqrt(- 18)
â–Ľ
Simplify
3sqrt(- 1* 24) * 2sqrt(- 1 * 18)
3 sqrt(- 1)* sqrt(24) * 2sqrt(- 1) * sqrt(18)
3 i* sqrt(24) * 2isqrt(18)
3 * 2 * i * i * sqrt(24) * sqrt(18)
6i^2 * sqrt(24)* sqrt(18)
6(- 1)* sqrt(24)* sqrt(18)
- 6* sqrt(24)* sqrt(18)
- 6* sqrt(24* 18)
- 6 sqrt(432)
Now we can simplify the square root.
- 6 sqrt(432)
- 6 sqrt(144 * 3)
- 6 sqrt(144) * sqrt(3)
- 6 (12) * sqrt(3)
- 72sqrt(3)