Table of contents
- 0. Review of Algebra4h 18m
- 1. Equations & Inequalities3h 18m
- 2. Graphs of Equations43m
- 3. Functions2h 17m
- 4. Polynomial Functions1h 44m
- 5. Rational Functions1h 23m
- 6. Exponential & Logarithmic Functions2h 28m
- 7. Systems of Equations & Matrices4h 6m
- 8. Conic Sections2h 23m
- 9. Sequences, Series, & Induction1h 22m
- 10. Combinatorics & Probability1h 45m
1. Equations & Inequalities
The Imaginary Unit
Struggling with College Algebra?
Join thousands of students who trust us to help them ace their exams!Watch the first videoMultiple Choice
Simplify the given square root. −75
A
25i3
B
5i3
C
3i5
D
75i

1
Identify the expression inside the square root: \(-75\).
Recognize that the square root of a negative number involves the imaginary unit \(i\), where \(i = \sqrt{-1}\).
Rewrite the expression as \(\sqrt{-75} = \sqrt{75} \cdot \sqrt{-1} = \sqrt{75} \cdot i\).
Simplify \(\sqrt{75}\) by factoring it into \(\sqrt{25 \times 3} = \sqrt{25} \cdot \sqrt{3}\).
Calculate \(\sqrt{25} = 5\), so the expression becomes \(5 \cdot \sqrt{3} \cdot i = 5i\sqrt{3}\).
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