Advertisements
Advertisements
प्रश्न
Choose the correct alternative:
cos 45° = ?
विकल्प
sin 45°
sec 45°
cot 45°
tan 45°
Advertisements
उत्तर
sin 45°
cos 45° = `1/sqrt2`, sin 45° = `1/sqrt2`
∴ cos 45° = sin 45°.
APPEARS IN
संबंधित प्रश्न
Prove the following identities:
`(costhetacottheta)/(1 + sintheta) = cosectheta - 1`
If tan A = n tan B and sin A = m sin B, prove that `cos^2A = (m^2 - 1)/(n^2 - 1)`
`(cot^2 theta ( sec theta - 1))/((1+ sin theta))+ (sec^2 theta(sin theta-1))/((1+ sec theta))=0`
If `( cos theta + sin theta) = sqrt(2) sin theta , " prove that " ( sin theta - cos theta ) = sqrt(2) cos theta`
If `sec theta + tan theta = p,` prove that
(i)`sec theta = 1/2 ( p+1/p) (ii) tan theta = 1/2 ( p- 1/p) (iii) sin theta = (p^2 -1)/(p^2+1)`
Write the value of tan1° tan 2° ........ tan 89° .
Four alternative answers for the following question are given. Choose the correct alternative and write its alphabet:
sin θ × cosec θ = ______
What is the value of \[\sin^2 \theta + \frac{1}{1 + \tan^2 \theta}\]
If sec2 θ (1 + sin θ) (1 − sin θ) = k, then find the value of k.
\[\frac{\sin \theta}{1 + \cos \theta}\]is equal to
If sin θ + sin2 θ = 1, then cos2 θ + cos4 θ =
Prove the following identity :
`(1 - sin^2θ)sec^2θ = 1`
Prove the following identity :
`(tanθ + secθ - 1)/(tanθ - secθ + 1) = (1 + sinθ)/(cosθ)`
If `x/(a cosθ) = y/(b sinθ) "and" (ax)/cosθ - (by)/sinθ = a^2 - b^2 , "prove that" x^2/a^2 + y^2/b^2 = 1`
Prove that tan2Φ + cot2Φ + 2 = sec2Φ.cosec2Φ.
If tan α = n tan β, sin α = m sin β, prove that cos2 α = `(m^2 - 1)/(n^2 - 1)`.
Without using the trigonometric table, prove that
tan 10° tan 15° tan 75° tan 80° = 1
If cos (α + β) = 0, then sin (α – β) can be reduced to ______.
Prove the following that:
`tan^3θ/(1 + tan^2θ) + cot^3θ/(1 + cot^2θ)` = secθ cosecθ – 2 sinθ cosθ
Let x1, x2, x3 be the solutions of `tan^-1((2x + 1)/(x + 1)) + tan^-1((2x - 1)/(x - 1))` = 2tan–1(x + 1) where x1 < x2 < x3 then 2x1 + x2 + x32 is equal to ______.
