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
Email Id : anil_tondak@yahoo.com
Ph No.: 9811363962