ICSE Board Practice

ICSE Grade X - Trigonometrical Identities
Question 1
1.
    • In the given figure, if
    •  
    • CE
    • +
    • DE
    • =
    • 32 cm
    • ,
    • and
    • CD = 8 cm
    • ,
    • find
    • cos
      C
  • 8

    15
  • 10

    17
  • 8

    17
  • 6

    17
  • 8

    19
Question 2
2.
Which of the following are true?
a)
    • sin
      (
      180
        +  
      θ
      )
    • =
    •    
      sin
      θ
b)
    • cos
      (
      180
        +  
      θ
      )
    • =
    • sin
      θ
c)
    • tan
      (
      180
        +  
      θ
      )
    • =
    • tan
      θ
d)
    • tan
      (
      180
        +  
      θ
      )
    • =
    • cot
      θ
e)
    • cos
      (
      180
        +  
      θ
      )
    • =
    •    
      cos
      θ
f)
    • sin
      (
      180
        +  
      θ
      )
    • =
    • cos
      θ
  • {f,b,e}
  • {d,a,c}
  • {a,c,e}
  • {b,a}
  • {d,c}
Question 3
3.
    • Express
    •  
    • tan
      49°
    •  
    • in terms of
    •  
    • sin
      49°
  •  
     
    1

     
     

    1
       
    sin
    2
     
    49°
  •  
     

    1
       
    sin
    2
     
    49°
  •  
     
    1

     
     
    sin
    49°
  •  
     

    1
       
    sin
    2
     
    49°

     
     
    sin
    49°
  •  
     
    sin
    49°

     
     

    1
       
    sin
    2
     
    49°
Question 4
4.
In the given figure, △IJK is a right angle triangle with ∠K = 90° and JK = 14 cm. T is the mid-point of IK. Find the length of the altitude from K to IJ.
  • 7
    cm
  • 7



    2
    cm
  • 14



    3
    cm
  • 7

    2



    12
    cm
  • 14
    cm
Question 5
5.
    • The value of
    • tan
      178°
    • in terms of an angle between
    • and
    • 90°
    • is
  • tan
    88°
  •    
    cot
    88°
  •    
    tan
    88°
  • cot
    88°
Question 6
6.
    • Express
    •  
    • sec
      θ
    •  
    • in terms of
    •  
    • cosec
      θ
  •  
     
    cosec
    θ

     
     

    cosec
    2
     
    θ
       
    1
  •  
     
    1

     
     

    cosec
    2
     
    θ
       
    1
  •  
     

    cosec
    2
     
    θ
       
    1
  •  
     

    cosec
    2
     
    θ
       
    1

     
     
    cosec
    θ
  •  
     
    1

     
     
    cosec
    θ
Question 7
7.
Find the area of an isosceles triangle with base 8 cm and vertical angle 65°
  • 24.1138 cm
  • 27.1138 cm
  • 26.1138 cm
  • 25.1138 cm
Question 8
8.
A chord of 16 cm subtends an angle of 90° at the centre. Calculate its shortest distance from the centre
  • 9.0 cm
  • 10.0 cm
  • 8.0 cm
  • 6.0 cm
  • 7.0 cm
Question 9
9.
Which of the following are true?
a)
    • cot
      (
      270
         
      θ
      )
    • =
    • tan
      θ
b)
    • cosec
      (
      270
         
      θ
      )
    • =
    •    
      cosec
      θ
c)
    • sec
      (
      270
         
      θ
      )
    • =
    •    
      sec
      θ
d)
    • cosec
      (
      270
         
      θ
      )
    • =
    •    
      sec
      θ
e)
    • sec
      (
      270
         
      θ
      )
    • =
    •    
      cosec
      θ
f)
    • cot
      (
      270
         
      θ
      )
    • =
    • cot
      θ
  • {f,b,e}
  • {c,d}
  • {b,a}
  • {a,d,e}
  • {c,a,d}
Question 10
10.
    • sin
      54°
    • =
  •  
     
    cos
    60°
    cos
      +  
    sin
    60°
    sin
  •  
     
    sin
    60°
    cos
      +  
    cos
    60°
    sin
  •  
     
    cos
    60°
    cos
       
    sin
    60°
    sin
  •  
     
    sin
    60°
    cos
       
    cos
    60°
    sin