Example 4 - Minute hand of a watch is 1.5 cm long. How far - Finding Value of trignometric functions, given other functions

  1. Chapter 3 Class 11 Trigonometric Functions
  2. Serial order wise

Transcript

Example 4 The minute hand of a watch is 1.5 cm long. How far does its tip move in 40 minutes? (Use = 3.14). We know that = r Hence, r = minute hand of clock = 1.5 cm Now we know that Minute hand make 1 revolution in 1 hour and Hence we can say that Minute hand complete 360o in one hour So degree complete in 1 minute = 360/60 So degree complete in 40 minute = 360/60 40o = 240o Hence = 240o = 240o /(180 ) = 4 /3 Now Putting values in formula = r = 1.5 4 /3 = 0.5 4 = 2 = 2 3.14 = 6.28 cm

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Davneet Singh
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 8 years. He provides courses for Maths and Science at Teachoo. You can check his NCERT Solutions from Class 6 to 12.