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Name the Parts
Re(z) = x. Im(z) = y. Pure imaginary: x = 0, y != 0. Real: y = 0. 0 = 0 + 0i is still in C. Powers of i cycle every 4 (i, -1, -i, 1).
Choose Your Level
Name the Parts
What is it?
Re(z) = x. Im(z) = y. Pure imaginary: x = 0, y != 0. Real: y = 0. 0 = 0 + 0i is still in C. Powers of i cycle every 4 (i, -1, -i, 1).
In simple words
- Re(z) = x.
- 3 + 2i
- 7i pure imaginary
- State the rule, show the working, and check the answer.
Important terms
NAME THE PARTS: Re(z) = x. Im(z) = y. Pure imaginary: x = 0, y != 0. Real: y = 0. 0 = 0 + 0i is still in C. Powers of i cycle every 4 (i, -1, -i, 1).
NAME THE PARTS: Re(z) = x.
What you should learn
- State the rule or meaning of name the parts in easy words.
- Apply name the parts in a clear step-by-step solution.
- Check the conditions, working, and final answer for accuracy.
Examples
- 3 + 2i
- 7i pure imaginary
- i2 = -1
MAIN IDEA
Re(z) = x. Im(z) = y. Pure imaginary: x = 0, y != 0. Real: y = 0. 0 = 0 + 0i is still in C. Powers of i cycle every 4 (i, -1, -i, 1).
EXAM USE
Write the rule first: Re(z) = x. Substitute carefully, show one step per line, and check signs, restrictions, units, and the final result.
Recommended for Class 11
Full school-level explanation
Re(z) = x. Im(z) = y. Pure imaginary: x = 0, y != 0. Real: y = 0. 0 = 0 + 0i is still in C. Powers of i cycle every 4 (i, -1, -i, 1).
Understand the idea, then apply it:
WHAT — NAME THE PARTS
Re(z) = x. Im(z) = y. Pure imaginary: x = 0, y != 0. Real: y = 0. 0 = 0 + 0i is still in C. Powers of i cycle every 4 (i, -1, -i, 1).
WHY — Why it matters
This rule is a separate learning unit inside complex numbers recalled. It can be defined, applied, and checked in its own FBISE question.
HOW — How to answer
Write the rule first: Re(z) = x. Substitute carefully, show one step per line, and check signs, restrictions, units, and the final result.
MAIN IDEA
Re(z) = x. Im(z) = y. Pure imaginary: x = 0, y != 0. Real: y = 0. 0 = 0 + 0i is still in C. Powers of i cycle every 4 (i, -1, -i, 1).
Remember
- Re and Im
Examples
- 3 + 2i
- 7i pure imaginary
- i2 = -1
EXAM USE
Write the rule first: Re(z) = x. Substitute carefully, show one step per line, and check signs, restrictions, units, and the final result.
Remember
- focused answer
- accurate support
Examples
- State the central idea
- Use one accurate detail
- Check the final response
How to answer a name the parts question
How it works
- Read the exact command word and identify what the question asks.
- State the matching idea, rule, or meaning before adding detail.
- Use the unit evidence or mathematical working that directly supports the answer.
- Check accuracy, relevance, and answer length before finishing.
Remember
- Re and Im
- z = x + i y
- equal <-> both parts equal
- R inside C
- Re and Im
- focused answer
- accurate support
- Re and Im
Deeper understanding
Go beyond memorising Name the Parts. Connect the definition to reasons, relationships, exceptions, and exam wording.
Common mistakes
Exam focus
Core Idea
What to Know
Example or Evidence
How to Answer
Exam focus
Quick revision
- Re and Im
- z = x + i y
- equal <-> both parts equal
- R inside C
- NAME THE PARTS: Re(z) = x. Im(z) = y. Pure imaginary: x = 0, y != 0. Real: y = 0. 0 = 0 + 0i is still in C. Powers o
- NAME THE PARTS: Re(z) = x.
Reals are complex numbers with Im = 0. Do not say 'not complex' for 5.
For long answers on Name the Parts: define clearly → explain the main parts → give one example → state one exam caution.
Exam Focus
Exam Focus
Important points
- Re and Im
- z = x + i y
- equal <-> both parts equal
- R inside C
Important formulas
- Re and Im
- z = x + i y
- equal <-> both parts equal
Common exam traps
- Reals are complex numbers with Im = 0. Do not say 'not complex' for 5.
- Do not choose a formula before checking that its conditions fit the question.
Long question structure
Definition → key parts → example → exam caution
Common Mistakes
Common Mistakes
- Mistake
Reals are complex numbers with Im = 0. Do not say 'not complex' for 5.
- Mistake
Do not choose a formula before checking that its conditions fit the question.
- Mistake
Do not hide sign changes, restrictions, or skipped algebra steps.
- Mistake
Reals are complex numbers with Im = 0. Do not say 'not complex' for 5.
Revision Zone
60-Second Revision
Quick cues from this topic — use them for last-minute revision.
Re and Im
z = x + i y
equal <-> both parts equal
R inside C
Re(z) = x. Im(z) = y. Pure imaginary: x = 0, y != 0. Real: y = 0. 0 = 0 + 0i is still in C. Powers of i cycle every 4 (i, -1, -i, 1).
z = x + i y
- Definition
- Re(z) = x. Im(z) = y. Pure imaginary: x = 0, y != 0. Real: y = 0. 0 = 0 + 0i is still in C. Powers of i cycle every 4 (i, -1, -i, 1).
- Formula
- z = x + i y
- Example
- 3 + 2i
- Critical warning
- Reals are complex numbers with Im = 0. Do not say 'not complex' for 5.
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Exam Practice
Define
Q1. Define Name the Parts.
Explain
Q2. Explain: MAIN IDEA.
Example
Q3. Give one clear example of Name the Parts and say why it fits.
Mistake
Q4. State one common mistake students make about Name the Parts.
Exam note
Q5. Write a short exam note on Name the Parts: definition, two points, one example.
Sources & References
School-standard facts for Matric and Intermediate. Original explanations — not copied from textbooks.