Search for: If 0<θ,ϕ<π/2 and x=∑n=0∞ sin2nϕ, y=∑n=0∞ cos2nθ and z=∑n=0∞ cosn(θ+ϕ)cosn(θ−ϕ), then If 0<θ,ϕ<π/2 and x=∑n=0∞ sin2nϕ, y=∑n=0∞ cos2nθ and z=∑n=0∞ cosn(θ+ϕ)cosn(θ−ϕ), then Axyz+1=yz-zxBxyz-1=yz+zxCxyz-xy=yz-zxDxyz+1=yz+zx 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 have x=11−sin2ϕ=1cos2ϕ,y=11−cos2θ=1sin2θ,Also, cos(θ+ϕ)cos(θ−ϕ)=cos2ϕ−sin2θ=1x−1yAs, 0<cos2ϕ<1,0<sin2θ<1,−1<cos2ϕ−sin2θ<1⇒ −1<1x−1y<1Thus, z=∑n=0∞ 1x−1yn=11−1x−1y=xyxy−y+x⇒ z(xy−y+x)=xy or xyz−xy=yz−xz Related content Top 5 Reasons To Study Science After 10th Application for Teaching Job Railway Jobs After 10th CBSE Class 12 Computer Science Answer Key and Paper Analysis 2024 – Student Feedback and Expert View Fractions Class 6 Worksheet Genetics and Evolution | Mind Map Kerala NEET UG Merit List 2023 NEET Exam Centres in Hyderabad 2024 Ecology & Environments NEET Exam Centres in Maharashtra 2024