Let $\alpha, \beta \in \mathbf{N}$ be roots of the equation $x^2-70 x+\lambda=0$, where $\frac{\lambda}{2}, \frac{\lambda}{3} \notin \mathbf{N}$. If $\lambda$ assumes the minimum possible value, then $\frac{(\sqrt{\alpha-1}+\sqrt{\beta-1})(\lambda+35)}{|\alpha-\beta|}$ is equal to :
Answer (integer)
60
Solution
<p>$$\begin{aligned}
& x^2-70 x+\lambda=0 \\
& \alpha+\beta=70 \\
& \alpha \beta=\lambda \\
& \therefore \alpha(70-\alpha)=\lambda
\end{aligned}$$</p>
<p>Since, 2 and 3 does not divide $\lambda$</p>
<p>$\therefore \alpha=5, \beta=65, \lambda=325$</p>
<p>By putting value of $\alpha, \beta, \lambda$ we get the required value $60$.</p>
About this question
Subject: Mathematics · Chapter: Complex Numbers and Quadratic Equations · Topic: Complex Numbers and Argand Plane
This question is part of PrepWiser's free JEE Main question bank. 223 more solved questions on Complex Numbers and Quadratic Equations are available — start with the harder ones if your accuracy is >70%.