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Which identity is proved first in this chain?
Acosec2 + cot2 = 1
Bsin2 - cos2 = 1
Csin2 + cos2 = 1
Dsec2 - tan2 = 2
Answer & Solution
Correct answer: C. sin2 + cos2 = 1
1. One identity follows straight from Pythagoras.
2. The others are then derived from it.
3. That first identity is sin squared plus cos squared equals 1.
4. So the answer is sin2 + cos2 = 1.
_Source: NCERT Class 10 Mathematics, Ch 8 'Introduction to Trigonometry'_
Related questions
Ratios are also defined for angles of measure 0 and:If the sides about the right angle are 3k and 4k, the hypotenuse is:tan A can be written as sin A divided by:The identity cosec2 A equals 1 plus:The identity sec2 A minus tan2 A equals:An equation true for all values of the angle is called an:The value of cosec 30 degrees is:The value of sin 30 degrees is: