The correct answer is: 6
\(l=∫_3^b \frac{1}{(x^2-1)(x^2-4)}dx=\frac{1}{3}(\frac{1}{x^2-4}-\frac{1}{x^2-1})dx\)
\(=ln((\frac{b-2}{b+2})\frac{(b+1)^2}{b-1}^2)-(In\,\frac{4}{5})\)
After simplification ,
\(\frac{49}{40}=\frac{(b-2)}{(b+2)}\frac{(b+1)^2}{(b-1)^2}.\frac{5}{4}\)
⇒ b = 6
Which one of the following graphs accurately represents the plot of partial pressure of CS₂ vs its mole fraction in a mixture of acetone and CS₂ at constant temperature?

Let \( \alpha = \dfrac{-1 + i\sqrt{3}}{2} \) and \( \beta = \dfrac{-1 - i\sqrt{3}}{2} \), where \( i = \sqrt{-1} \). If
\[ (7 - 7\alpha + 9\beta)^{20} + (9 + 7\alpha - 7\beta)^{20} + (-7 + 9\alpha + 7\beta)^{20} + (14 + 7\alpha + 7\beta)^{20} = m^{10}, \] then the value of \( m \) is ___________.
The number of formulas used to decompose the given improper rational functions is given below. By using the given expressions, we can quickly write the integrand as a sum of proper rational functions.

For examples,
