MEDIUM
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Prove that sin 405°cos 300°-cos 420°sin 585°=sin 45°

Important Questions on Trigonometric Ratios and Identities

MEDIUM
In a triangle ABC, the altitude AD and the median AE divide A into three equal parts. If BC=28, then the nearest integer to AB+AC is
EASY
If sinα+β=1, sinα-β=12,α,β0,π2 then the value of  tan(α+2β)tan(2α+β) is
MEDIUM
Let ABC be an isosceles triangle with AB=AC and incentre I. If AI=3 and the distance from I to BC is 2, what is the square of the length of BC?
MEDIUM
The angle of the top of a vertical tower standing on a horizontal plane is observed to be 45° from a point A on the plane. Let B be the point 30 m vertically above the point A. If the angle of elevation of the top of the tower from B be 30° , then the distance (in m) of the foot of the tower from the point A is:
HARD
Let AB be a diameter of a circle and let C be a point on the segment AB such that AC:CB=6:7. Let D be a point on the circle such that DC is perpendicular to AB. Let DE be the diameter through D. If XYZ denotes the area of the triangle XYZ, find ABDCDE to the nearest integer.
MEDIUM

Let P=(θ:sinθ-cosθ=2cosθ} and Q={θ:sinθ+cosθ=2sinθ} be two sets. Then,

EASY
The combined equation of the two diameters of a circle which divide the circle into 4 sectors is ax2+2hxy+by2=0. If the area of the bigger sector is 5 times the area of the smaller sector, then a+ba-b2+4h2=
MEDIUM
Two vertical poles AB=15 m and CD=10 m are standing apart on a horizontal ground with points A and C on the ground. If P is the point of intersection of BC and AD, then the height of P (in m) above the line AC is:
MEDIUM
Two parallel chords are drawn on the same side of the centre of a circle of radius 20. It is found that they subtend 60° and 120° angles at the centre of the circle, then the perpendicular distance between the chords is
HARD
Suppose ABCDEF is a hexagon such that AB=BC=CD=1 and DE=EF=FA=2. If the vertices A,B,C,D,E,F are concylic, the radius of the circle passing through them is-
EASY
If 5sinx=3, then what is the value of (secx-tanx)(secx+tanx)+5?
EASY
An ant leaves the anthill for its morning exercise. It walks 4 feet east and then makes a 160° turn to the right and walks 4 more feet. It then makes another 160° turn to the right and walks 4 more feet. If the ant continues this pattern until it reaches the anthill again, what is the distance in feet it would have walked?
EASY
Let ACB be a triangle with right-angle at C. Let AB=29 units, BC=21 units and ABC=θ. Then cos2θ-sin2θ=
EASY

Read the given question and decide which of the following information is sufficient to answer the question.

What is the value of 0?

Information :

Question Image

(II) 0 < q < 90°

EASY
If tanA+cotA=2, then the value of tan4 A+cot4 A=
MEDIUM
Let P be a closed polygon with 10 sides and 10 vertices (assume that the sides do not intersect except at the vertices). Let k be the number of interior angles of P that are greater than 180o. The maximum possible value of k is