Advertisements
Advertisements
प्रश्न
Prove that 2 tan 80° = tan 85° – tan 5°.
Advertisements
उत्तर
Consider tan 80° = tan(85° – 5°)
`= (tan 85° - tan 5°)/(1 + tan 85° tan 5°)`
`= (tan 85° - tan 5°)/(1 + tan 85° tan (90° - 85°))`
`= (tan 85^circ - tan 5^circ)/(1 + tan 85^circ xx cot 85^circ)`
`= (tan 85^circ - tan 5^circ)/(1 + 1)`
`= (tan 85^circ - tan 5^circ)/2`
∴ 2 tan 80° = tan 85° – tan 5°
Hence Proved.
APPEARS IN
संबंधित प्रश्न
Find the value of the following:
cosec 15º
Find the value of the following:
cos 70° cos 10° – sin 70° sin 10°
Prove that:
tan 4A tan 3A tan A + tan 3A + tan A – tan 4A = 0
If sin A = `12/13`, find sin 3A.
If tan α = `1/7`, sin β = `1/sqrt10`. Prove that α + 2β = `pi/4` where 0 < α < `pi/2` and 0 < β < `pi/2`.
Prove that cot 4x (sin 5x + sin 3x) = cot x(sin 5x - sin 3x).
Find the value of sin 75°.
If sin A + cos A = 1 then sin 2A is equal to:
The value of 1 – 2 sin2 45° is:
The value of `(2 tan 30^circ)/(1 + tan^2 30^circ)` is:
