Arts (English Medium) कक्षा ११ - CBSE Question Bank Solutions for Mathematics

Mark the correct alternative in each of the following: 

In a ∆ABC, if a = 2, \[\angle B = 60°\]  and\[\angle C = 75°\] 

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If the sides of a triangle are in the ratio \[1: \sqrt{3}: 2\] then the measure of its greatest angle is 

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In any ∆ABC, 2(bc cosA + ca cosB + ab cosC) = 

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In a triangle ABC, a = 4, b = 3, \[\angle A = 60°\]   then c is a root of the equation 

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In a ∆ABC, if  \[\left( c + a + b \right)\left( a + b - c \right) = ab\] then the measure of angle C is 

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In any ∆ABC, the value of  \[2ac\sin\left( \frac{A - B + C}{2} \right)\]  is 

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In any ∆ABC, \[a\left( b\cos C - c\cos B \right) =\]  

Find the value of `(1 + cos  pi/8)(1 + cos  (3pi)/8)(1 + cos  (5pi)/8)(1 + cos  (7pi)/8)`

If x cos θ = `y cos (theta + (2pi)/3) = z cos (theta + (4pi)/3)`, then find the value of xy + yz + zx.

If x = sec Φ – tan Φ and y = cosec Φ + cot Φ then show that xy + x – y + 1 = 0
[Hint: Find xy + 1 and then show that x – y = –(xy + 1)]