Advertisements
Advertisements
प्रश्न
Write the value of cos1° cos 2°........cos180° .
उत्तर
Cos 1° cos 2° … cos 180°
= cos 1° cos 2° … cos 90° … cos 180°
= cos 1° cos 2° … 0 … cos 180°
= 0
APPEARS IN
संबंधित प्रश्न
Prove the following trigonometric identities.
`cot theta - tan theta = (2 cos^2 theta - 1)/(sin theta cos theta)`
If m = a sec A + b tan A and n = a tan A + b sec A, then prove that : m2 – n2 = a2 – b2
Prove the following identities:
`cosecA - cotA = sinA/(1 + cosA)`
`(1+ cos theta)(1- costheta )(1+cos^2 theta)=1`
`1+(tan^2 theta)/((1+ sec theta))= sec theta`
`(tan A + tanB )/(cot A + cot B) = tan A tan B`
Show that none of the following is an identity:
(i) `cos^2theta + cos theta =1`
Show that none of the following is an identity:
`tan^2 theta + sin theta = cos^2 theta`
Write the value of `(1 + tan^2 theta ) cos^2 theta`.
Prove that:
`"tan A"/(1 + "tan"^2 "A")^2 + "Cot A"/(1 + "Cot"^2 "A")^2 = "sin A cos A"`.
Simplify : 2 sin30 + 3 tan45.
If sin2 θ cos2 θ (1 + tan2 θ) (1 + cot2 θ) = λ, then find the value of λ.
If cos \[9\theta\] = sin \[\theta\] and \[9\theta\] < 900 , then the value of tan \[6 \theta\] is
Prove the following identity :
`sinθ(1 + tanθ) + cosθ(1 +cotθ) = secθ + cosecθ`
Without using trigonometric identity , show that :
`sec70^circ sin20^circ - cos20^circ cosec70^circ = 0`
Prove that `(sin (90° - θ))/cos θ + (tan (90° - θ))/cot θ + (cosec (90° - θ))/sec θ = 3`.
If tan α = n tan β, sin α = m sin β, prove that cos2 α = `(m^2 - 1)/(n^2 - 1)`.
Prove that `cos θ/sin(90° - θ) + sin θ/cos (90° - θ) = 2`.
(sec θ + tan θ) . (sec θ – tan θ) = ?
Prove that `(cos^2theta)/(sintheta) + sintheta` = cosec θ
