Question

Without using the trigonometric tables, evaluate
11 sin 70° 4 cos 53° cosec 37°
7 cos 20° 7 tan 15°tan 35 tan 55° tan 75​

Answer 1

Answer:

2156

Step-by-step explanation:

Without using the trigonometric tables, evaluate

11 sin 70° 4 cos 53° cosec 37°  7 cos 20° 7 tan 15°tan 35 tan 55° tan 75​

Correction in question : cos 20° should be sec20°

11 Sin70° * 4 Cos53° * Cosec37° * 7 Sec20° * 7 Tan15° * Tan 35° * Tan 55° * Tan 75°

Cosec37° = 1/Sin37°  = 1/Cos(90 - 37)° = 1/Cos53°

Sec20° = 1/Cos20° = 1/Sin(90 - 20)° = 1/Sin70°

Tan 55° = 1/Tan(90 - 55)° = 1/Tan35°

Tan 75° = 1/Tan(90 - 75)° = 1/Tan15°

Putting all these values

= 11 Sin70° * 4 Cos53° * 7 * 7 Tan15° * Tan 35° / (Cos53° * Sin70° * Tan35° * Tan 15°)

= 11 * 4 * 7 * 7

= 44 * 49

= 2156