Quadratic Equations · NDA previous year questions

2009 7 questions

1. Q102009 · 19 Apr 2009

   Which one of the following is one of the roots of the equation $(b-c)x^2+(c-a)x+(a-b)=0$?

   1. A.$(c-a)/(b-c)$
   2. B.$(a-b)/(b-c)$
   3. C.$(b-c)/(a-b)$
   4. D.$(c-a)/(a-b)$
   Show answer

   Answer: B

2. Q112009 · 19 Apr 2009

   What is the value of $x$ satisfying the equation $16{\left(\frac{a-x}{a+x}\right)}^3=\frac{a+x}{a-x}$?

   1. A.$a/2$
   2. B.$a/3$
   3. C.$a/4$
   4. D.$0$
   Show answer

   Answer: B

3. Q122009 · 19 Apr 2009

   If $\alpha ,\beta$ are the roots of the equation $2x^2-2(1+n^2)x+(1+n^2+n^4)=0$, then what is the value of ${\alpha }^2+{\beta }^2$?

   1. A.$2n^2$
   2. B.$2n^4$
   3. C.$2$
   4. D.$n^2$
   Show answer

   Answer: D

4. Q132009 · 19 Apr 2009

   The roots of $A{x}^2+Bx+C=0$ are $r$ and $s$. For the roots of $x^2+px+q=0$ to be $r^2$ and $s^2$, what must be the value of $p$?

   1. A.$(B^2-4AC)/A^2$
   2. B.$(B^2-2AC)/A^2$
   3. C.$(2AC-B^2)/A^2$
   4. D.$B^2-2C$
   Show answer

   Answer: C

5. Q142009 · 19 Apr 2009

   What is the value of $r$ if $P(5,r)=P(6,r-1)$?

   1. A.$9$
   2. B.$5$
   3. C.$4$
   4. D.$2$
   Show answer

   Answer: C

6. Q152009 · 19 Apr 2009

   What is the number of words formed from the letters of the word 'JOKE' so that the vowels and consonants alternate?

   1. A.4
   2. B.8
   3. C.12
   4. D.None of the above
   Show answer

   Answer: B

7. Q452009 · 19 Apr 2009

   If $(x+a)$ is a factor of both the quadratic polynomials $x^2+px+q$ and $x^2+lx+m$, where $p,q,l$ and $m$ are constants, then which one of the following is correct?

   1. A.$a=(m-q)/(l-p),(l\ne p)$
   2. B.$a=(m+q)/(l+p),(l\ne -p)$
   3. C.$l=(m-q)/(a-p),(a\ne p)$
   4. D.$p=(m-q)/(a-l),(a\ne l)$
   Show answer

   Answer: A