Question
A vertical tower stands on a horizontal plane and is
surmounted by a vertical flag staff of height h. At a point on the plane, the angle of elevation of the bottom of the flag staff is and that of the top of the flag staff is β. Then the height of the tower isSolution
Apply tan 
 in ∆BCD Tan  = x / K k = (x / tan ) ---- (1) apply tanβ in ∆ACD => tanβ = (ĥ+x) / K => K = (h + x) / (tanβ) ----- (2) Example like (1) and (2) => x / tan  = (h+x) / tanβ => xtanβ = tan h + xtan => xtanβ – xtan  = h tan => x(tanβ – tan ) = h tan => x = (h tan2) / (tanβ – tan )
230 192 172 ? 122 100
...What value should come in the place of (?) in the following number series?
64, 80, 104, ?, 176, 224
97, 106, ?, 195, 411, 460
What will come in place of the question mark (?) in the following series?
29, 42, ?, 95, 135, 184
Find the missing term:
2, 6, 15, 31, 56, ?
32   48   96   ?   720   2520
82, 98, 130, 178, 242, ?
4 10 ? 62.5 156.25 390.625
...140, 146, 170, 224, ?, 470
7 47 ? 223 359 527
...
Relevant for Exams:
