Monday, 27 October 2014

XI Revision assignment Binomial theorem



                 DCM PRESIDENCY SCHOOL, LUDHIANA
                          MATHS – ASSIGNMENT, CLASS- 11TH TOPIC -  BINOMIAL THEOREM

1.  Find the number of terms in the following expansion;
      a)   (1+2x+x2)20  b) [(3x+y)8 –(3x-y)8]
2.   Using binomial theorem expand :       a)  (1 + x +x2)3  b)  (10.1)5
3.   Using binomial theorem , prove that  23n -7n -1 is divisible by 49, n€N.
4.  Find the 11th  term from the end of the expansion  (2x – 1/x2)25.
5.  Find the coffiecients of x32 and x-17  in the expansion (x4- 1/x3)15
6.  If the fourth term in the expansion (ax+ 1/x)n  is 5/2, then find the value of a and n.
7.  Using the binomial , prove that 6n -5n always leave the remainder 1 , when divisible by 25.
8.  Prove that the coefficient of the middle term in the expansion of (1 +x)2n is equal to the sum of the        coefficient of middle term of the expansion (1+x)2n-1
9.  In the binomial expansion of (1+x)n, the coefficient of the 5th ,6th , and 7th terms are in A. P . Find all  values of n for which this can happen.
10.  The coefficient of three consecutive term in the expansion(1+x)n be 76, 95, 76, find n.

XI Revision assignment trigonometry

                       DCM PRESIDENCY SCHOOL, LUDHIANA

                          MATHS – ASSIGNMENT, CLASS- 11TH TOPIC -             TRIGONOMETRY

1.        Find the value of  (a)  sin 315   (b)   cos 210    (c)   sin (-1125)
2.        If 2tanβ + cot β = tan α , prove that cot β = 2 tan(α - β).
3.        If A + B = π/4 , Prove that ;
       (i)  (1 + tanA) (1 – tan B)  = 2    (ii) (cotA - 1)(cot B - 1) =2
4.        If tan ( α +β) = n tan(α - β) , show that (n + 1)sin 2β = (n -1) sin 2α
5.        If tan A – tan B = x and cot B – cot A = y , prove that cot(A - B) = 1/X + 1/y
6.        Prove that cos 20 cos 40 cos 60 cos 80 = 1/16
7.        Prove that sin 10 sin 30 sin50 sin70 =  1/16
8.        Prove that sin 20 sin 40 sin 60 sin80 = 3/16
9.        Prove that sin A sin ( 60 -A) sin (60 + A) = ¼ sin 3A
10.   Prove that 1 + cos 2x + cos 4x + cos 6x = 4 cos x cos2x cos 3x
11.   Prove that tan α + 2tan 2α + 4 tan 4α + 8cot 8α = cotα.
12.   Prove that cos2A + cos2(A + 2π/3) + cos2 (A - 2π/3) = 3/2
13.   Prove that cos α + cosβ + cos γ + cos (α +β +γ) = 4 cos α +β /2 cos β +γ/2 cos     γ +α/2
14.   Prove that sinx /sin 3x + sin 3x /cos 9x + sin 9x /cos27x = ½ (tan 27x - tanx)
15.   If cos α +cos β + cosγ = 0 then  prove that , cos3α + cos 3β + cos 3γ = 12 cosα cosβ cosγ
16.   Solve the following equations
(i)                4 cos A -  3 sec A = tan A   (ii)  tan θ  + tan 2θ + tanθ tan2θ = 1
 (iii) tan θ + tan 2θ + tan 3θ = tanθ tan2θ tan 3θ

     17  Prove  that tan 70 = tan 20 + 2 tan 50
    18  Prove that sinα + sin (α + 2π/ 3 ) + sin ( α + 4π/ 3) = 0
    19. If sin α + sinβ = a and  cosα + cosβ = b prove that  cos (α -β) = a2 + b2 – 2 /2
    20  If 3 tan A tan B  = 1  , prove that  2 cos ( A + B) = cos ( A - B )  
    21. 4 Sin α Sin ( α + π/3) Sin (α + 2π/3 ) = Sin 3α.
    22. If A+ B+ C = 180 Prove that Sin 2A + Sin 2B – Sin 2C = 4 Cos A Cos B Sin C
    23.Prove that Sin 51 + Cos 81 = Cos 21
    24. Prove that tan A + tan( 60 + A) + tan(120 + A) = 3 tan 3A
    25. Solve the equation  Cos 3x + 8 Cos3x = 0