Find f sin 2 x/ 9 - cos4 x dx

This question is similar to Example 42 - Chapter 7 Class 12 - Integrals

[Class 12 Term 2 SQP] Find Integration ∫ 𝑠𝑖𝑛2π‘₯ √9βˆ’π‘π‘œπ‘ 4π‘₯ 𝑑x - CBSE Class 12 Sample Paper for 2022 Boards (For Term 2)

part 2 - Question 1 (Choice 2) - CBSE Class 12 Sample Paper for 2022 Boards (For Term 2) - Solutions of Sample Papers and Past Year Papers - for Class 12 Boards - Class 12
part 3 - Question 1 (Choice 2) - CBSE Class 12 Sample Paper for 2022 Boards (For Term 2) - Solutions of Sample Papers and Past Year Papers - for Class 12 Boards - Class 12

Remove Ads

Transcript

Question 1 – Choice 2 Find ∫1β–’γ€–sin⁑2π‘₯/√(9 βˆ’ cos^4⁑π‘₯ ) 𝑑π‘₯γ€—Now, ∫1β–’γ€–sin⁑2π‘₯/√(9 βˆ’ cos^4⁑π‘₯ ) 𝑑π‘₯γ€—=∫1β–’γ€–(𝟐 𝐬𝐒𝐧⁑𝒙 πœπ¨π¬β‘π’™)/√(πŸ— βˆ’(〖𝒄𝒐𝒔〗^πŸβ‘π’™ )^𝟐 ) 𝒅𝒙〗 Let 〖𝒄𝒐𝒔〗^πŸβ‘π’™=𝒕 Differentiating both sides w.r.t.π‘₯ 2 cos⁑π‘₯ Γ— βˆ’sin⁑π‘₯=𝑑𝑑/𝑑π‘₯ 𝒅𝒙=𝒅𝒕/(β€“πŸ 𝒄𝒐𝒔⁑𝒙 π’”π’Šπ’β‘π’™ ) Hence, our equation becomes ∫1β–’γ€–(𝟐 𝐬𝐒𝐧⁑𝒙 πœπ¨π¬β‘π’™)/√(πŸ— βˆ’(〖𝒄𝒐𝒔〗^πŸβ‘π’™ )^𝟐 ) 𝒅𝒙〗 =∫1β–’γ€–(2 sin⁑π‘₯ cos⁑π‘₯)/√(9 βˆ’ 𝑑^2 ) 𝑑π‘₯γ€— =∫1β–’γ€–(2 sin⁑π‘₯ cos⁑π‘₯)/√(9 βˆ’ 𝑑^2 )×𝒅𝒕/(β€“πŸ 𝒄𝒐𝒔⁑𝒙 π’”π’Šπ’β‘π’™ )γ€— =βˆ’βˆ«1▒𝑑𝑑/√((3)^2 βˆ’ (𝑑)^2 ) =βˆ’[sin^(βˆ’1)⁑〖𝑑/3+𝐢1γ€— ] =βˆ’π’”π’Šπ’^(βˆ’πŸ) 𝒕/πŸ‘+π‘ͺ It is of form ∫1▒〖𝒅𝒙/√(𝒂^𝟐 βˆ’ 𝒙^𝟐 )=π’”π’Šπ’^(βˆ’πŸ) 𝒙/𝒂+π‘ͺγ€— Replacing π‘₯ by 𝑑 and π‘Ž by 3, we get Putting back 𝒕=〖𝒄𝒐𝒔〗^πŸβ‘π’™ =βˆ’π’”π’Šπ’^(βˆ’πŸ) [𝟏/πŸ‘ 𝒄𝒐𝒔^𝟐 𝒙]+π‘ͺ

Davneet Singh's photo - Co-founder, Teachoo

Made by

Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 14 years. He provides courses for Maths, Science and Computer Science at Teachoo