Question
Speed of a boat in still water is 3 times more than the
speed of stream. If boat covers 90 km in downstream in 6 hours, then find the time taken by the boat to cover 63 km in upstream.Solution
Let the speed of stream be ‘x’ km/hr. So, speed of boat in still water = 4 × x = 4x km/hr Downstream speed of boat = 4x + x = 5x km/hr According to question; 5x = 90/6 = 15 Or, x = 3 Upstream speed of the boat = 4x – x = 3x = 3 × 3 = 9 km/hr Required time taken = 63/9 = 7 hours
If cos1.5B = sin(B + 5°), then find the measure of 'B'.
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If secθ + tanθ = 5/2 for an acute angle θ, find sinθ.
If tanθ – cotθ = a and cosθ + sinθ = b, then (b2 –1)(a2 + 4) = ?
cos A (sec A – cos A) (cot A + tan A) = ?
If cos3B = sin(0.5B + 6°), then find the measure of 'B'.
Find the value of the given trigonometric expression:
(sin 22°cos 68° + cos²22°) × sin 30° + (cos 60°tan 45°) × sec 60°
...- If sin(A + B) = √3/2 and cos(A + 2B) = 1/2, where 0° < A, B < 90°, then find the value of tan(2A).

(cos5°+sin5°)/(cos5°-sin5°) is equal to: