Search for: If f(x)=cosx⋅cos2x⋅cos4x⋅cos8x⋅cos16x then the value of f′π4 is If f(x)=cosx⋅cos2x⋅cos4x⋅cos8x⋅cos16x then the value of f′π4 is A1B2C12D0 Fill Out the Form for Expert Academic Guidance!l Grade ---Class 1Class 2Class 3Class 4Class 5Class 6Class 7Class 8Class 9Class 10Class 11Class 12 Target Exam JEENEETCBSE +91 Preferred time slot for the call ---9 am10 am11 am12 pm1 pm2 pm3 pm4 pm5 pm6 pm7 pm8pm9 pm10pm Please indicate your interest Live ClassesBooksTest SeriesSelf Learning Language ---EnglishHindiMarathiTamilTeluguMalayalam Are you a Sri Chaitanya student? NoYes Verify OTP Code (required) I agree to the terms and conditions and privacy policy. Solution:We know that,cosAcos2Acos22A…cos2n−1A =sin2nA2nsinA∴cosxcos2xcos4xcos8xcos16x=sin32x32sinx⇒ f(x)=132⋅sin32xsinx∴ f′(x)=132×sinx(32cos32x)−sin32xcosxsin2x⇒ f′π4=1sinπ4=2 Related content Nucleus Diagram for Class 9 Neuron Diagram Class 9 Human Heart Diagram Class 10 CBSE Class 7 Science Chapter 1 Nutrition in Plants MCQ Questions with Answers CBSE Class 9 English Worksheet – The Road not Taken 50+ GK Questions and Answers for Class 8 “Kabir Ki Sakhiyan” MCQ Questions for Class 9 Hindi with Answers Kshitij, Kritika, Sparsh, Sanchayan Bhag 1 CBSE Class 7 English Honeycomb Chapter 1 Three Questions MCQ Questions with Answers CBSE Class 9 English Beehive Book Poem 1 The Road Not Taken MCQ Questions with Answers MCQs Questions with Answers for Class 9 English Chapter 1 The Fun They Had