MathematicsChapter 8: Application of Trigonometry
Reference
150 deg -> 30 deg. 120 deg -> 60 deg.
Learning objectives
- Define and explain reference.
- Apply reference to a focused FBISE question.
- Check the answer for correct terms, evidence, working, and units.
Definition
150 deg -> 30 deg. 120 deg -> 60 deg. 125 deg -> 55 deg. 3pi/4 rad is 135 deg, reference 45 deg. Keep the same trig of the reference, then attach the quadrant sign.
Where / symbols
- Reference
- 150 deg -> 30 deg. 120 deg -> 60 deg. 125 deg -> 55 deg. 3pi/4 rad is 135 deg, reference 45 deg. Keep the same trig of the reference, then attach the quadrant sign.
Overview
Learn the idea, then use it:
Core Understanding
150 deg -> 30 deg. 120 deg -> 60 deg. 125 deg -> 55 deg. 3pi/4 rad is 135 deg, reference 45 deg. Keep the same trig of the reference, then attach the quadrant sign.
Examples acute to axis · reference to the x-axis · ASTC signs · REFERENCE: 150 deg -> 30 deg. 120 deg -> 60 deg. 125 deg -> 55 deg. 3pi/4 rad is 135 deg, reference 45 deg. Keep the same trig of t
Exam Application
State the correct term, connect it to the chapter rule or evidence, and use a clear example or calculation.
Examples Define first · Show the rule or evidence · Check units, labels, and conclusion
WHAT — REFERENCE
150 deg -> 30 deg. 120 deg -> 60 deg. 125 deg -> 55 deg. 3pi/4 rad is 135 deg, reference 45 deg. Keep the same trig of the reference, then attach the quadrant sign.
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.
In simple words
Do not merge reference with a neighbouring idea that uses a different definition, rule, or method.
Key points
- acute to axis
- reference to the x-axis
- ASTC signs
Exam preparation
Exam Focus
Quick revision
Revision Zone
Review the key facts, formulas and checks before you move on.Reference
Sticky Notes · Quick Revision
Core Idea
- 150 deg -> 30 deg.
Key Points
- acute to axis
- reference to the x-axis
- ASTC signs
Simple Check
- Explain reference in your own words and connect it to one chapter example.
How to Answer
- Define the idea, show the main rule or evidence, apply it, and check the final statement.
Common Mistake
- Do not merge reference with a neighbouring idea that uses a different definition, rule, or method.
FBISE Exam Tip
- Use the exact term, show working where needed, and include units or labelled evidence.
60-second revision
- 150 deg -> 30 deg.
- acute to axis
- reference to the x-axis
- ASTC signs
Did you understand this topic?
Your answer is saved with your learning record. It does not mark the topic as mastered.