question_answer

P and Q are two distinct points on the parabola, \[{{y}^{2}}=4x\], with parameters t and \[{{t}_{1}}\] respectively. If the normal at p passes through Q, then the minimum value of \[t_{1}^{2}\] is   JEE Main Online Paper (Held On 10 April 2016)

A) 4                                

B) 6

C) 8                

D) 2

Correct Answer: C

Solution :

             \[{{t}_{1}}=-t-\frac{2}{t}\] \[t_{1}^{2}={{t}^{2}}+\frac{4}{{{t}^{2}}}+4\] min of \[t_{1}^{2}=8\]