Advertisements
Advertisements
प्रश्न
If `sqrt(3)` sin θ – cos θ = θ, then show that tan 3θ = `(3tan theta - tan^3 theta)/(1 - 3 tan^2 theta)`
Advertisements
उत्तर
If `sqrt(3)` sin θ – cos θ = θ
To prove tan 3θ = `(3tan theta - tan^3 theta)/(1 - 3 tan^2 theta)`
`sqrt(3)` sin θ – cos θ = θ
`sqrt(3)` sin θ = cos θ
`sin theta/cos theta = 1/sqrt(3)`
tan θ = tan 30°
θ = 30°
L.H.S = tan 3θ°
= tan3 (30°)
= tan 90°
= undefined (α)
R.H.S = `(3tan theta - tan^3 theta)/(1 - 3 tan^2 theta)`
= `(3tan30^circ - tan^2 30^circ)/(1 - 3tan^2 30^circ)`
= `3(1/sqrt(3)) - (1/sqrt(3))^3 ÷ 1 - 3 xx (1/sqrt(3))^2`
= `sqrt(3) - 1/(3sqrt(3)) ÷ 1 - 3 xx 1/3`
= `(9 - 1)/(3sqrt(3)) ÷ 1 - 1`
= `8/(3sqrt(3)) ÷ 0`
= undefined (α)
∴ tan 3θ = `(3tan theta - tan^3 theta)/(1 - 3 tan^2 theta)`
APPEARS IN
संबंधित प्रश्न
If `sec alpha=2/sqrt3` , then find the value of `(1-cosecalpha)/(1+cosecalpha)` where α is in IV quadrant.
Prove the following trigonometric identities.
sec6 θ = tan6 θ + 3 tan2 θ sec2 θ + 1
Prove the following trigonometric identities.
`(1 + tan^2 A) + (1 + 1/tan^2 A) = 1/(sin^2 A - sin^4 A)`
Prove the following identities:
`(1 + (secA - tanA)^2)/(cosecA(secA - tanA)) = 2tanA`
`(1 + cot^2 theta ) sin^2 theta =1`
Prove the following identity :
`(1 - sin^2θ)sec^2θ = 1`
Prove the following identity :
`sec^2A + cosec^2A = sec^2Acosec^2A`
Prove the following identity :
`(tanθ + sinθ)/(tanθ - sinθ) = (secθ + 1)/(secθ - 1)`
The value of sin2θ + `1/(1 + tan^2 theta)` is equal to
Prove the following:
`sintheta/(1 + cos theta) + (1 + cos theta)/sintheta` = 2cosecθ
