Find the interval/s in which the function f:R→R defined by f(x)=xe^x, is increasing

This question is similar to Ex 6.2 ,19 Chapter 6 Class 12

Find the intervals in which function f(x) = xe^x is increasing [Video] - CBSE Class 12 Sample Paper for 2024 Boards

part 2 - Question 22 - CBSE Class 12 Sample Paper for 2024 Boards - Solutions of Sample Papers and Past Year Papers - for Class 12 Boards - Class 12
part 3 - Question 22 - CBSE Class 12 Sample Paper for 2024 Boards - Solutions of Sample Papers and Past Year Papers - for Class 12 Boards - Class 12

 

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Let f(š‘„) = š‘„š‘’^š‘„ Finding f’(š’™) f’(š‘„) = (š‘„š‘’^š‘„ )′ Using product rule f’(š‘„) = (š‘„)′ š‘’^š‘„ + (š‘’^š‘„ )’ (š‘„) f’(š‘„) = (1) š‘’^š‘„ + (š‘’^š‘„ ) (š‘„) f’(š‘„) = š‘’^š‘„+š‘’^š‘„ š‘„ f’(š’™) = e š’™ (šŸ+š’™) Putting f’(š’™)=šŸŽ e š’™ (šŸ+š’™) =šŸŽ 1+š‘„ = 0 So, š‘„=āˆ’1 Plotting points on real line Hence, f(š‘„) is increasing on [āˆ’šŸ ,āˆž)

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