Question
sin2 9 ° + sin2 10 ° +
sin2 11 ° + sin2 12 ° + ……… + sin2 81 ° = ?Solution
sin2 9 ° + sin2 10 ° + sin2 11 ° + sin2 12 ° + ……… + sin2 81 ° = (sin 2 9 ° + sin2 81 °)+(sin2 8 ° + sin2 82 °) + .…. + (sin2 44 ° + sin2 46 °) + sin2 45 ° = (sin2 9 ° + cos2 9 °)+(sin2 10 °+ cos2 10 °) + .…. + (sin2 44 ° + cos2 44 °)+ sin2 45 °  {As sin (90 ° - θ) = cos θ} = (1)+(1) + .…. upto 36 times + sin2 45 ° { As sin2 θ + cos2 θ= 1} = 36 + sin2 45 °                 = 36 + (1/√2)2 {As sin 45 ° =1/√2 } = 36 + 
 = 36.5
18 + 28 ÷ 4 - 14 = ? - 35
...The value of 3 × 7 + 5 – 6 ÷ 3 – 9 + 45 ÷ 5 × 4 – 45  is:
√(?) = (897 × 51) ÷ 1016.6
(122 - 82 ) of 52 + 52 = ?2Â
What will come in the place of question mark (?) in the given expression?
? = (266 × 276) ÷ (114 × 161) × 17
The valueof2 of5– 1/2 −[4÷2– 1/3 −{3/4−(5– 1/2 – 3/4 )}]is :
13 X √? + 256 ÷ 4 = 30% of 900 - 50
666(2/3)% of 30 - 116(2/3)% of 90 =?
? × 5.5 = √1225 + 40% of 30% of 37.5% of 5000 – 63
Evaluate: 144 ÷ 12 × 6 + 35 − 4²
