Let speed of boat in upstream and downstream be ‘7x’ km/h and ‘9x’ km/h respectively. 91/7x + 126/9x = 9 13/x + 14/x = 9 27 = 9x x = 3 Speed of boat in still water = (7x + 9x)/2 = 8x = 8 × 3 = 24 km/h Desired time = 180/24 = 7.5 hours
The angle of depression of two ships from the top of a light house are 45º and 30º. if the ships are 120m on the opposite sides of li...
Simplify: sin (A + B) sin (A - B)
cot 4˚ x cot 47˚ x cot 42.3˚ x cot 43˚ x cot 47.7˚ x cot 86˚= ?
If 2y . cos θ - x . sin θ = 0 and 2x . sec θ - y . cosec θ = 3, what is the value of x² + 4y²?
From a point 50 meters away from the base of a tower, the angle of elevation of the top of the tower is 30°. Find the height of the tower.
If x = r sin A cos B, y = r sin A sin B and z = r cos A, then find x² + y² + z².
What is the value of [tan2 (90 – θ) – sin2 (90 – θ)] cosec2 (90 – θ) cot2 (90 – θ)?
...If 2sin y + cos y = √3 sin y, then find the value of tan y
