Comprehension

Directions: Read the following information and answer the two items that follow:

Consider the equation xy = ex-y

What is  at x = 1 equal to?

This question was previously asked in
NDA (Held On: 17 Nov 2019) Maths Previous Year paper
View all NDA Papers >
  1. 0
  2. 1
  3. 2
  4. 4

Answer (Detailed Solution Below)

Option 1 : 0
Free
NDA 01/2025: English Subject Test
30 Qs. 120 Marks 30 Mins

Detailed Solution

Download Solution PDF

Concept:

Calculation:

Given: xy = ex-y

By applying ln both the sides we get

⇒ y × ln x = ln (ex-y) = x – y

⇒ y × ln x = x – y

⇒ x = y × (1 + ln x)      ------(1)

Now by differentiating both the sides with respect to x we get,

Now by using equation (1), we get

So, 

Latest NDA Updates

Last updated on Jun 18, 2025

->UPSC has extended the UPSC NDA 2 Registration Date till 20th June 2025.

-> A total of 406 vacancies have been announced for NDA 2 Exam 2025.

->The NDA exam date 2025 has been announced. The written examination will be held on 14th September 2025.

-> The selection process for the NDA exam includes a Written Exam and SSB Interview.

-> Candidates who get successful selection under UPSC NDA will get a salary range between Rs. 15,600 to Rs. 39,100. 

-> Candidates must go through the NDA previous year question paper. Attempting the NDA mock test is also essential. 

Hot Links: teen patti 3a teen patti online teen patti joy apk teen patti fun all teen patti master