5 min read
Check
If you claim (2+3i)(1+i) = -1+5i, expand the left again. If you claim a quotient is i, multiply i by the old denominator and compare with the numerator.
Choose Your Level
Check
What is it?
If you claim (2+3i)(1+i) = -1+5i, expand the left again. If you claim a quotient is i, multiply i by the old denominator and compare with the numerator.
In simple words
- If you claim (2+3i)(1+i) = -1+5i, expand the left again.
- multiply back
- a + bi finished
- check by reverse
Important terms
Check: If you claim (2+3i)(1+i) = -1+5i, expand the left again. If you claim a quotient is i, multiply i by the old denominator and compare with the numerator.
What you should learn
- Define and explain check.
- Apply check to a focused FBISE question.
- Check the answer for correct terms, evidence, working, and units.
Examples
- multiply back
- a + bi finished
- check by reverse
CORE UNDERSTANDING
If you claim (2+3i)(1+i) = -1+5i, expand the left again. If you claim a quotient is i, multiply i by the old denominator and compare with the numerator.
EXAM APPLICATION
State the correct term, connect it to the chapter rule or evidence, and use a clear example or calculation.
Recommended for Class 10
Full school-level explanation
If you claim (2+3i)(1+i) = -1+5i, expand the left again. If you claim a quotient is i, multiply i by the old denominator and compare with the numerator.
Learn the idea, then use it:
WHAT — CHECK
If you claim (2+3i)(1+i) = -1+5i, expand the left again. If you claim a quotient is i, multiply i by the old denominator and compare with the numerator.
HOW — Use the idea
Identify what is given, select this topic's rule or evidence, apply it one step at a time, and check the result.
CORE UNDERSTANDING
If you claim (2+3i)(1+i) = -1+5i, expand the left again. If you claim a quotient is i, multiply i by the old denominator and compare with the numerator.
Remember
- multiply back
- a + bi finished
- check by reverse
Examples
- multiply back
- a + bi finished
- check by reverse
- CHECK: If you claim (2+3i)(1+i) = -1+5i, expand the left again. If you claim a quotient is i, multiply i by the old denominator
EXAM APPLICATION
State the correct term, connect it to the chapter rule or evidence, and use a clear example or calculation.
Remember
- correct term
- chapter link
- clear application
Examples
- Define first
- Show the rule or evidence
- Check units, labels, and conclusion
Remember
- multiply back
- a + bi finished
- check by reverse
- keep the ideas separate
- multiply back
- a + bi finished
- check by reverse
- correct term
Deeper understanding
Go beyond memorising Check. Connect the definition to reasons, relationships, exceptions, and exam wording.
Common mistakes
Exam focus
Core Idea
Key Points
Simple Check
How to Answer
Exam focus
Quick revision
- multiply back
- a + bi finished
- check by reverse
- keep the ideas separate
- Check: If you claim (2+3i)(1+i) = -1+5i, expand the left again. If you claim a quotient is i, multiply i by
- WHAT — CHECK: If you claim (2+3i)(1+i) = -1+5i, expand the left again. If you claim a quotient is i, multiply i by
Do not merge check with a neighbouring idea that uses a different definition, rule, or method.
For long answers on Check: define clearly → explain the main parts → give one example → state one exam caution.
Exam Focus
Exam Focus
Important points
- multiply back
- a + bi finished
- check by reverse
- keep the ideas separate
Important formulas
- multiply back
- a + bi finished
- check by reverse
Common exam traps
- Do not merge check with a neighbouring idea that uses a different definition, rule, or method.
- Do not invent a formula, fact, unit, or diagram label that the chapter does not support.
Long question structure
Definition → key parts → example → exam caution
Common Mistakes
Common Mistakes
- Mistake
Do not merge check with a neighbouring idea that uses a different definition, rule, or method.
- Mistake
Do not invent a formula, fact, unit, or diagram label that the chapter does not support.
- Mistake
Do not merge check with a neighbouring idea that uses a different definition, rule, or method.
Revision Zone
60-Second Revision
Quick cues from this topic — use them for last-minute revision.
multiply back
a + bi finished
check by reverse
keep the ideas separate
If you claim (2+3i)(1+i) = -1+5i, expand the left again. If you claim a quotient is i, multiply i by the old denominator and compare with the numerator.
- Definition
- If you claim (2+3i)(1+i) = -1+5i, expand the left again. If you claim a quotient is i, multiply i by the old denominator and compare with the numerator.
- Example
- multiply back
- Critical warning
- Do not merge check with a neighbouring idea that uses a different definition, rule, or method.
Did you understand this topic?
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Exam Practice
Define
Q1. Define Check.
Explain
Q2. Explain: CORE UNDERSTANDING.
Example
Q3. Give one clear example of Check and say why it fits.
Mistake
Q4. State one common mistake students make about Check.
Exam note
Q5. Write a short exam note on Check: definition, two points, one example.
Sources & References
School-standard facts for Matric and Intermediate. Original explanations — not copied from textbooks.