Comprehension

निम्न दो (02) प्रश्नों के लिए निम्नलिखित पर विचार कीजिए :

x और y के सभी वास्तविक मानों के लिए एक फलन इस प्रकार है कि f(xy) = f(x + y) और f(5) = 10 है। 

. f(20) + f(- 20) किसके बराबर है?

This question was previously asked in
NDA-I (Mathematics) Official Paper (Held On: 13 Apr, 2025)
View all NDA Papers >
  1. 0
  2. 10
  3. 20
  4. 40

Answer (Detailed Solution Below)

Option 3 : 20
Free
NDA 01/2025: English Subject Test
5.7 K Users
30 Questions 120 Marks 30 Mins

Detailed Solution

Download Solution PDF

गणना:

दिया गया है,

फलन \( f(xy) = f(x + y) \) है, जहाँ x और y के सभी वास्तविक मान हैं, और f(5) = 10 है।

हमें ज्ञात करना है:

\( f(20) + f(-20) \)

दिए गए फलन समीकरण का उपयोग करके, हमारे पास है:

\( f(0 \cdot 5) = f(0 + 5) \) के लिए, हमें मिलता है:

\( f(0) = f(5) = 10 \)

\( f(0 \cdot 20) = f(0 + 20) \) के लिए, हमें मिलता है:

\( f(0) = f(20) = 10 \)

\( f(0 \cdot -20) = f(0 + (-20)) \) के लिए, हमें मिलता है:

\( f(0) = f(-20) = 10 \)

इस प्रकार,

\( f(20) + f(-20) = 10 + 10 = 20 \)

इसलिए, सही उत्तर विकल्प 3 है।

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. 

More Relations and Functions Questions

Get Free Access Now
Hot Links: teen patti real cash teen patti gold old version teen patti 100 bonus teen patti master king