JEE Advanced 2015Paper 1
- Exam
- JEE Advanced
- Year
- 2015
- Paper
- Paper 1
- Subject
- Mathematics
- Chapter
- Sequences and Series
JEE Advanced 2015 · Paper 1 · Mathematics · Sequences and Series
Column I Column II ( A ) In ℝ ^ 2 , if the magnitude of the...
| Column I | Column II | |||
| In , if the magnitude of the projection vector of the vector \alpha\overset{^}{i} + \beta\overset{^}{j} on \sqrt{3}\overset{^}{i} + \overset{^}{j} is and if then possible value (s) is (are) | \left(P\right)( B )f\left(x\right) = \left\{\right) is differentiable for all Then possible value (s) of a is (are) | \left(Q\right)( C )\omega \ne 1{\left(3 - 3\omega + 2{\omega}^{2}\right)}^{4n + 3} + {\left(2 + 3\omega - 3{\omega}^{2}\right)}^{4n + 3} + {\left(- 3 + 2\omega + 3{\omega}^{2}\right)}^{4n + 3} = 0 | 3 | |
| Let the harmonic mean of two positive real numbers a and b 4. If q is a positive real number such that a, 5, q, b is an arithmetic progression, then the value (s) of |q – a| is (are) | 4 | |||
| (T) | 5 | |||
Options
- Aa-t;b-t;c-q;d-s;
- Ba-s,t;b-r,s,t;c-q,r,s;d-t;
- Ca-p,q;b-p,q;c-p,q,s,t;d-q,t;
- Da-r,s;b-s,t;c-s,t;d-q,r,s,t;
Correct answer
C. a-p,q;b-p,q;c-p,q,s,t;d-q,t;
Step-by-step solution
\left(A\right) ...(i)
And, also ...(ii)
Solving (i) & (ii), we get
So, and
i.e, \left|\alpha\right| = 2, 1( B )- 3a - 2 = b + {a}^{2}- 6a = b- 3a - 2 = - 6a + {a}^{2}⇒ {a}^{2} - 3a + 2 = 0⇒ a = 1, 2 Here, ⇒ {\left(3 - 3\omega + 2{\omega}^{2}\right)}^{4n + 3}\left\{1 + {\omega}^{4n} + {\omega}^{8n}\right\} = 0n = 1, 2, 4, 5q - a = 2dq - q = \alpha, d = \dfrac{\alpha}{2}a = 5 - \dfrac{\alpha}{2}, b = a + \dfrac{3\alpha}{2} = 5 + \alpha\dfrac{ab}{a + b} = 2⇒ \dfrac{\left(5 - \dfrac{\alpha}{2}\right)\left(5 + \alpha\right)}{5 - \dfrac{\alpha}{2} + 5 + \alpha} = 2⇒ \alpha = 5, - 2
And, also ...(ii)
Solving (i) & (ii), we get
So, and
i.e, \left|\alpha\right| = 2, 1( B )- 3a - 2 = b + {a}^{2}- 6a = b- 3a - 2 = - 6a + {a}^{2}⇒ {a}^{2} - 3a + 2 = 0⇒ a = 1, 2 Here, ⇒ {\left(3 - 3\omega + 2{\omega}^{2}\right)}^{4n + 3}\left\{1 + {\omega}^{4n} + {\omega}^{8n}\right\} = 0n = 1, 2, 4, 5q - a = 2dq - q = \alpha, d = \dfrac{\alpha}{2}a = 5 - \dfrac{\alpha}{2}, b = a + \dfrac{3\alpha}{2} = 5 + \alpha\dfrac{ab}{a + b} = 2⇒ \dfrac{\left(5 - \dfrac{\alpha}{2}\right)\left(5 + \alpha\right)}{5 - \dfrac{\alpha}{2} + 5 + \alpha} = 2⇒ \alpha = 5, - 2