Engineering Board Exam Reviewer · Complex Numbers: Operations · medium

Find the roots of z2+2z+5=0.

1. -1 2i
2. 1 2i
3. -1 4i
4. -2 2i

Answer

A. -1 2i

Solution

z= -2 (4-20)2=-2 4i/2=-1 2i.

More Complex Numbers: Operations questions

1. Find the modulus of (3+4i)(5-12i).
2. Evaluate (1+i)8.
3. Simplify 5+5i/1-2i.
4. Simplify (3+2i)(4-5i).
5. Simplify: i2001
6. Simplify: i15+i18
7. Add: (3+5i)+(2-7i)
8. Multiply: (4+3i)(2-i)
9. Divide: 3+4i/1-2i
10. Find the absolute value (modulus) of 5-12i.

All Complex Numbers: Operations questions