The Islamic Institution For                              In his name
Education & Teaching                                     Mid-year term                           Mathematics Department
                                                                                                   February 2013
  Subject: Mathematics                                                                               Mark : ------ /
  Grade 11(S)                                                                                          Duration: 150 minutes
 I. ( points)
   One, among the following answers, is true. Choose it after you justify your answer.
  Question                                                                A                      B                     C
1 a & b are two real numbers such that :
   3a  3b  8                                                                                                   8
                                                                  8                                           x2  x 1  0
   ab  1                                                    x2  x 1  0            3x  8 x  3  0
                                                                                          2
                                                                                                                   3
                                                                   3
  then a & b are the roots of the quadratic
  equation:
2                   3                                                     3                     3x                   6x
   If h( x)               then h '(x)=
                   x2 1                                           ( x 2  1) x 2  1     ( x 2  1) x 2  1    ( x 2  1) x 2  1
3 The value of m for which
   f ( x)  mx 3  (m  6) x  7  0 admits an extremum                   7                      1                     9
           1                                                              6                      2                     2
  at x0= is:
           3
 II. ( points)
     Consider the second degree equation ( E ) : x 2  2mx  m 2  m  5  0 with m is a real parameter.
        1. Calculate  or  ' and discuss according to the values of m the existence of the roots of
             Equation (E).
        2. Without calculating the roots x1 & x2 ,determine m so that the roots of the equation (E)
             Verify the relation ( x1  1)( x2  1)  12
 III.
  1. Calculate the following limits:
              x 2  2x  3
     a. lim 2               
         x 1 3 x  2 x  1
                1  sin   1
     b. lim                    
          0        
               (cos2 x  cos x)
     c. lim                         
         x 0 cos 2 x  3 cos x  2
                     x2  a2
                                if x  0
                     x2
  2. Given f ( x)  
                     x  a  1 if x  0
                    
                         2
     Calculate a so that f is continuous at x0 = 0.
                                                               1
IV. ( points)
                                                                         Un  3
 Consider the sequences (Un) and (Vn) defined by U0= 1, Un+1=                   and Vn= Un + 3.
                                                                           2
   1. Calculate V0 , V1 and V2.
   2. Prove that (Vn) is a geometric sequence whose common ratio is to be determined.
   3. Express Vn and Un in terms of n.
                        n
   4. Calculate S n  Vi then deduce S ' n  U 1  U 2  ...........  U n .
                       i 0
V. ( points)
  Given the circle (C) of equation: x 2  2 x  y 2  4 y  4  0
     1. Determine the center I and the radius R of circle (C).
     2. Does line of equation ( y=-x) cuts circle ( C) ?If yes , determine the coordinates of the points of
        intersection .
VI. ( points)
                                                3
 1. Let x be a real number such that x ];        [ with sinx = -0.8.
                                                 2
        a. Calculate cosx and sin2x.
        b. Find tan2x.
                                                       5
 2. Given A ] , [ and (tanA. tanB) = -1 and (A + B) =    .
               2                                         6
                                    3
       a. Show that tan(A+B)= 
                                   3
                                          3
       b. Show that tan A + tan B=  2
                                         3
 3. Given a direct triangle ABC.
        a. Show that sin(2A)+sin(2B)+sin(2C)= 4 sin A .sin B . sin C
                                 cos A        cos B        cos C
        b. Deduce that :                                           2
                              sin B. sin C sin A. sin C sin A. sin B
VII. ( points)                                                                            y
                                                                                          4
 Consider the curve (C ) of a function f
                                                                                          3
                                                                                                           (C)
                                                              2                           2
                                                                                -2   -1    0   1   2   3    4 x
                                                                                          -1
 Note: (C) cuts x'Ox at 0 and at 3
         (C) admits a horizontal tangent at x = 0 and at x = 2 .
    1. Set up the table of variations of f .
    2. Solve graphically: f(x) <0; f(x)≥ 0 ; f ' (x) =0 .
    3. Discuss graphically according to the values of
        m the number of roots of the equation f(x)= m .
    4. One of the graphs (H) or (G) below represents the
      Derivative function f ' of f .
      a. Determine the graph of f '. Justify your answer.
      b. Write the equation of the tangent to (C ) at x= 1 .
                  y                                                        y
                  6
                                                                                            (G)
                                                                          4
                  5
                  4                                                       3
                  3                                                       2
                  2                                                       1
                  1
                                       (H)
                                                            -2       -1    0   1    2   3         4 x
         -1       0      1       2      3    x                            -1
              -1
                                                                          -2
              -2
              -3
                                                                          -3
   5. Assume that f is defined by: f(x) = ax3+bx2+cx .
     Use (C ) to calculate a, b and c .
VIII. ( points)
                                                                 1 4 3 2
   Consider the function f defined over IR by f ( x)              x  x  2x  2
                                                                 4    2
   and let (C) be its representative curve.
   1. Determine the limits of f at   and   .
   2. Verify that f ( x)  x 3  3 x  2  ( x  2)( x  1) 2
   3.   Set up the table of variation of f.
   4.   Deduce that f (x) =0 admits two distinct roots  &  .
   5.   Show that f admits two inflection points to be determined.
   6.   Given that  ] - 3;-2.5[ &  ]  1;0.5[ ;
      Draw (C) in an orthonormal system.
   7. Deduce (C') the graph of g where g(x) = f (x) .
                                                                                                        GOOD WORK!