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प्रश्न
Which is not correct formula?
पर्याय
1 + tan2θ = sec2θ
1 + sec2θ = tan2θ
cosec2θ – cot2θ = 1
sin2θ + cos2θ = 1
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उत्तर
1 + sec2θ = tan2θ
Explanation:
(A) 1 + tan2θ = sec2θ: Correct. This is a fundamental Pythagorean identity.
(B) 1 + sec2θ = tan2θ: Incorrect. Rearranging the correct identity from (A) gives sec2θ – 1 = tan2θ.
(C) cosec2θ – cot2θ = 1: Correct. This is derived from the standard identity 1 + cot2θ = cosec2θ.
(D) sin2θ + cos2θ = 1: Correct. This is the primary Pythagorean trigonometric identity.
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संबंधित प्रश्न
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Activity:
L.H.S. = `square`
= `cos^2θ xx square` ...`[1 + tan^2θ = square]`
= `(cos θ xx square)^2`
= 12
= 1
= R.H.S.
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