Conjugate — Algebra II, what it means and where it is taught
a - bi is the conjugate of a + bi. Multiplying them clears the i entirely.
Taught in Algebra II.
Where it is taught
Practise this idea
3 questions in the course bank use Conjugate, in Complex Numbers.
Problem 1
Give the conjugate of 4-7i.
Worked answer
4+7i
4+7i
Problem 2
Simplify 103-i.
Worked answer
3+i
Bottom: (3-i)(3+i)=9+1=10
Top: 10(3+i)=30+10i
30+10i10=3+i
Problem 3
Simplify 1+i1-i.
Worked answer
i
Bottom: (1-i)(1+i)=1+1=2
Top: (1+i)2=1+2i-1=2i
2i2=i