A tower of 45 cm high costs a shadow of 12 cm, then the angle of elevation of the dun is
-45°
-35°
-65°
-75°
The correct option is (D): -75°
If \( \alpha>\beta>\gamma>0 \), then the expression \[ \cot^{-1} \beta + \left( \frac{1 + \beta^2}{\alpha - \beta} \right) + \cot^{-1} \gamma + \left( \frac{1 + \gamma^2}{\beta - \gamma} \right) + \cot^{-1} \alpha + \left( \frac{1 + \alpha^2}{\gamma - \alpha} \right) \] is equal to:
The molar conductivities at infinite dilution for Na2SO4,K2S04,KCl, HCl and HCOONa at 300K are 260, 308, 150, 426, and 105 S cm2 mol-1, respectively. What will be A+m for formic acid in the same unit?
Calculate the Reynold’s number for a liquid of density 1 g/cm3, viscosity 8 x 10-4 Pa.s flowing at 0.5 m/s through a pipe of diameter 4 cm?
Which of the following statement is true for aqueous solution of 0.1 M urea, 0.2 M glucose nad 0.3 M sucrose
Electrophilic halogenation of phenol does not require catalyst because
The relationship between the sides and angles of a right-angle triangle is described by trigonometry functions, sometimes known as circular functions. These trigonometric functions derive the relationship between the angles and sides of a triangle. In trigonometry, there are three primary functions of sine (sin), cosine (cos), tangent (tan). The other three main functions can be derived from the primary functions as cotangent (cot), secant (sec), and cosecant (cosec).
sin x = a/h
cos x = b/h
tan x = a/b
Tan x can also be represented as sin x/cos x
sec x = 1/cosx = h/b
cosec x = 1/sinx = h/a
cot x = 1/tan x = b/a