Advertisements
Advertisements
प्रश्न
Without using trigonometric identity , show that :
`sec70^circ sin20^circ - cos20^circ cosec70^circ = 0`
Advertisements
उत्तर
`sec70^circ sin20^circ - cos20^circ cosec70^circ = 0`
Consider `sec70^circ sin20^circ - cos20^circ cosec70^circ`
⇒ `sec(90^circ - 20^circ)sin20^circ - cos20^circ . cosec(90^circ - 20^circ)`
⇒ `cosec20^circ sin20^circ - cos20^circ sec20^circ`
⇒ `1/sin20^circ . sin20^circ - cos20^circ . 1/cos20^circ`
⇒ 1 - 1 = 0
APPEARS IN
संबंधित प्रश्न
Express the ratios cos A, tan A and sec A in terms of sin A.
Prove the following trigonometric identity:
`sqrt((1 + sin A)/(1 - sin A)) = sec A + tan A`
Prove the following trigonometric identities.
`[tan θ + 1/cos θ]^2 + [tan θ - 1/cos θ]^2 = 2((1 + sin^2 θ)/(1 - sin^2 θ))`
Prove the following identities:
`(1 - 2sin^2A)^2/(cos^4A - sin^4A) = 2cos^2A - 1`
Prove the following identities:
(1 + tan A + sec A) (1 + cot A – cosec A) = 2
Write the value of ` sin^2 theta cos^2 theta (1+ tan^2 theta ) (1+ cot^2 theta).`
Prove the following identity :
(secA - cosA)(secA + cosA) = `sin^2A + tan^2A`
Prove the following identity :
`1/(tanA + cotA) = sinAcosA`
Prove that (cosec A - sin A)( sec A - cos A) sec2 A = tan A.
Prove that 2(sin6A + cos6A) – 3(sin4A + cos4A) + 1 = 0.
