Error detection in standard values
Error detection in standard values means finding and correcting wrong entries in the standard trigonometric value table.
Practice This ConceptMain explanation
Teacher explanation
This skill is important because CBSE often tests whether students truly know the values or only memorized them partly. The most common errors are swapping 30 degrees and 60 degrees, confusing sine with cosine, and forgetting that tan 90 degrees is not defined. Careful comparison is the best way to catch mistakes.
Example
If a table shows cos 60 degrees as root 3 over 2, that is wrong because cos 60 degrees should be 1/2.
Simple analogy
Thirty and sixty swap, forty-five stays the same, and ninety needs special care.
Common confusion
Students often accept a wrong table entry because it looks similar to a correct one.
Exam tip
Check the pair pattern: 30 degrees and 60 degrees are complements, while 45 degrees stays equal in sine and cosine.
Answer writing and exam use
1-mark use
Write the exact meaning of error detection in standard values in one clean line.
2-mark use
Define error detection in standard values and add one example or condition.
3-mark use
Explain error detection in standard values, show the method or example, and mention the common mistake.
Practice this concept with focused MCQs
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