CBSE Guess > Papers > Important Questions > Class XI > 2010 > Maths > Maths By Mr. Anil Kumar Tondak
CBSE CLASS XI
Q.62. If tana = -2, find the values of the remaining trigonometric functions of a.
Q.63. If x lies in IIIrd quadrana and sin x = 
find sin 
and Cos 
Q.64. If sin q = 3/5,cos f = -12/13and q, f both lie in IInd quadrant, find the value of tan (q + f)
Q.65. If Cos q = 
and p < q < 
find the value of 
Q.66. If sin A = 
and cos B = 
, Where 0 < A, B < 
, find the values of the following :
(i) sin (A+B) (ii) cos (A+B) (iii) sin (A-B) (iv) cos (A-B)
Q.67. If cos A = 
and cos B = 
, Where p < A < 
,
Q.68. Find the following :
(i) sin (A+B) (ii) cos (A+B)
Q.69. If tanx = 
, p<x<
, Find the values of sin x/2, cos x/2 and tan x/2.
Q.70. If 0 £ x £ 2p and x lies in the IInd quadrant such that sin x = 
Find the values of cos
Q.71. Prove that: Cos 
.
Q.72. If A + B +C = Л, Prove that:
(i) Cos2A + Cos2B – Cos2C = 1 – 2SinA.SinB.CosC
(ii)
(iii)
Q.73. If A + B = C Prove that: cos2A + cos2B + cos2C = 1 + 2 cosA cosB cosC.
Prove that: (i) (sin 3A + sin A) sin A + (cos 3A – cos A) cos A = 0
. (ii) cos 2 q cos 
- cos 3q cos 
= sin 5 q sin 
Q.74 Prove that:
cos a + cos b + cos g + cos (a + b + g) = 4 cos 
Q.75. Prove that : 
Q.76. If 
prove that 
Q.77. Prove that:
(a) 
(b) 
(c) 
(d) 
Q.78. If sin 2A = l sin 2B, prove that: 
Q.79. If cos θ + sin θ = √2 cos θ , prove that cos θ – sin θ = √2 sin θ
Q .80. If 
, Prove that 
Q.81. If 
, Prove that (i) 
(ii) 
Q.82. Prove that cot x cot 2x - cot 2x cot 3x - cot 3x cot x = 1
Q.83. Prove that:
(i) cos 4 
(ii) sin 4 
Q.84. Prove that : 
Q.85. Prove that : cos 
Q.86. Prove that: tan 4q = 
Q.87. Prove: cos 4 A = 1 – 8 cos2 A+8 cos4 A
Q.88. Prove: sin 4 A = 4 sin A cos3 A – 4 cos A sin3 A.
Q.89. Prove that: cos 6A = 32 cos6 A – 48 cos4 A + 18 cos2 A – 1
Q.90. Prove that : cos A cos (60-A) cos (60+A) = 
Paper By Mr. Anil Kumar Tondak
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Ph No.: 9811363962
