For any integer n, the value of ∫_(-Ο€)^Ο€ β€Še^(cos^2 x) sin^3 (2n+1)x dx is

(a) -1Β Β Β Β Β Β Β Β Β Β  (b) 0Β Β Β Β Β Β Β Β Β Β Β Β Β  (c) 1Β Β Β Β Β Β Β Β Β Β  (d) 2

-lock-

[MCQ] For any integer n, the value of ∫ e^(cos^2x) sin^3 (2n+1)x dx - CBSE Class 12 Sample Paper for 2024 Boards

part 2 - Question 9 - CBSE Class 12 Sample Paper for 2024 Boards - Solutions of Sample Papers and Past Year Papers - for Class 12 Boards - Class 12

-endlock-

Remove Ads
Teachoo Β· Class 12 Explore Class 12

Transcript

This is of the form ∫_(βˆ’π‘Ž)^π‘Žβ–’π‘“(π‘₯)𝑑π‘₯ where 𝒇(𝒙)=𝒆^(〖𝒄𝒐𝒔〗^𝟐 𝒙) γ€–π¬π’Šπ’γ€—^πŸ‘ (πŸπ’+𝟏)𝒙 And, 𝑓(βˆ’π‘₯)=𝑒^〖𝒄𝒐𝒔〗^𝟐⁑(βˆ’π’™) sin^3⁑〖[(2𝑛+1)γ€— (βˆ’π’™)] Since cos (-x) = cos x 𝑓(βˆ’π‘₯)=𝑒^(γ€–π‘π‘œπ‘ γ€—^2⁑π‘₯) γ€–s𝑖𝑛〗^3⁑[βˆ’(2𝑛+1)π‘₯] Since sin (-x) = βˆ’sin x 𝒇(βˆ’π’™)=γ€–βˆ’π’†γ€—^(〖𝒄𝒐𝒔〗^πŸβ‘π’™) γ€–π’”π’Šπ’γ€—^πŸ‘β‘(πŸπ’+𝟏)𝒙 Thus, 𝑓(βˆ’π‘₯)=βˆ’π‘“(π‘₯) ∴ ∫130_(βˆ’π…)^π…β–’β€Š 𝒆^(〖𝒄𝒐𝒔〗^𝟐 𝒙) γ€–π’”π’Šπ’γ€—^πŸ‘ (πŸπ’+𝟏)𝒙𝒅𝒙=𝟎 So, the correct answer is (b)

Davneet Singh's photo - Co-founder, Teachoo

Made by

Davneet Singh

Davneet Singh is an IIT Kanpur graduate and has been teaching for 16+ years. At Teachoo, he breaks down Maths, Science and Computer Science into simple steps so students understand concepts deeply and score with confidence.

Many students prefer Teachoo Black for a smooth, ad-free learning experience.