Advertisements
Advertisements
Question
Evaluate the following: cot20° cot40° cot45° cot50° cot70°
Advertisements
Solution
cot20° cot40° cot45° cot50° cot70°
= cot(90° - 70°) x cot(90° - 50°) x 1 x cot50° x cot70°
= tan70° x tan50° x cot50° x cot70°
= tan70° x cot70° x tan50° x cot50°
= `tan70° xx (1)/(tan70°) xx tan50° xx (1)/(tan50°)`
= 1.
APPEARS IN
RELATED QUESTIONS
In ΔABC, ∠B = 90° , AB = y units, BC = `(sqrt3)` units, AC = 2 units and angle A = x°, find:
- sin x°
- x°
- tan x°
- use cos x° to find the value of y.
Solve the following equation for A, if 2 sin A = 1
Calculate the value of A, if cos 3A. (2 sin 2A - 1) = 0
Find the value of 'A', if cosec 3A = `(2)/sqrt(3)`
If θ = 15°, find the value of: cos3θ - sin6θ + 3sin(5θ + 15°) - 2 tan23θ
If `sqrt(3)` sec 2θ = 2 and θ< 90°, find the value of
cos2 (30° + θ) + sin2 (45° - θ)
Find the value 'x', if:
Find x and y, in each of the following figure:
Express each of the following in terms of trigonometric ratios of angles between 0° and 45°: cos72° - cos88°
Evaluate the following: `(3sin^2 40°)/(4cos^2 50°) - ("cosec"^2 28°)/(4sec^2 62°) + (cos10° cos25° cos45° "cosec"80°)/(2sin15° sin25° sin45° sin65° sec75°)`
