Prove that: (sin𝒙 − cos𝒙 + 1). (sec𝒙 − tan𝒙) = (sin𝒙 + cos𝒙 − 1) - CBSE Class 10 Sample Paper for 2026 Boards - Maths Basic

part 2 - Question 30 - CBSE Class 10 Sample Paper for 2026 Boards - Maths Basic - Solutions of Sample Papers for Class 10 Boards - Class 10

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Question 30 Prove that : (sin𝒙 βˆ’ cos𝒙 + 1). (sec𝒙 βˆ’ tan𝒙) = (sin𝒙 + cos𝒙 βˆ’ 1)Solving LHS (𝑠𝑖𝑛 π‘₯βˆ’π‘π‘œπ‘  π‘₯+1) Γ— (𝑠𝑒𝑐 π‘₯ βˆ’π‘‘π‘Žπ‘› π‘₯) = (π’”π’Šπ’ π’™βˆ’π’„π’π’” 𝒙+𝟏) Γ— (𝟏/πœπ¨π¬β‘π’™ βˆ’π¬π’π§β‘π’™/πœπ¨π¬β‘π’™ ) = (𝑠𝑖𝑛 π‘₯βˆ’π‘π‘œπ‘  π‘₯+1) Γ— ((1 βˆ’ sin⁑π‘₯)/cos⁑π‘₯ ) = (1+𝑠𝑖𝑛 π‘₯βˆ’π‘π‘œπ‘  π‘₯) Γ— ((1 βˆ’ sin⁑π‘₯)/cos⁑π‘₯ ) = ([1+𝑠𝑖𝑛 π‘₯]βˆ’π‘π‘œπ‘  π‘₯) Γ— ((1 βˆ’ sin⁑π‘₯)/cos⁑π‘₯ ) = (𝟏+𝐬𝐒𝐧⁑𝒙 ) Γ— ((𝟏 βˆ’ π’”π’Šπ’β‘π’™)/𝒄𝒐𝒔⁑𝒙 )βˆ’πœπ¨π¬β‘π’™ Γ—((𝟏 βˆ’ π’”π’Šπ’β‘π’™)/𝒄𝒐𝒔⁑𝒙 ) = ((1 + sin⁑π‘₯ )(1 βˆ’ sin⁑π‘₯))/cos⁑π‘₯ βˆ’(1βˆ’sin⁑π‘₯) = (𝟏 βˆ’ 〖𝐬𝐒𝐧〗^πŸβ‘π’™)/cos⁑π‘₯ βˆ’(1βˆ’sin⁑π‘₯) Putting 1 – sin2 x = cos2 x = γ€–πœπ¨π¬γ€—^πŸβ‘π’™/cos⁑π‘₯ βˆ’(1βˆ’sin⁑π‘₯) = π‘π‘œπ‘  π‘₯βˆ’(1βˆ’sin⁑π‘₯) = π‘π‘œπ‘  π‘₯βˆ’1+sin⁑π‘₯ = (π’”π’Šπ’ 𝒙+𝒄𝒐𝒔 π’™βˆ’πŸ)

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