Let I=\(\int_{0}^{1} \frac{x}{ x^2+1},dx\)
Let x2+1=t⇒2x dx=dt
When x=0,t=1 and when x=1,t=2
∴\(\int_{0}^{1} \frac{x}{ x^2+1},dx\)=\(\frac 12\)\(∫^2_1\)\(\frac{dt}{t}\)
=\(\frac 12\)\([log|t|]^2_1\)
=\(\frac 12\)[log2-log1]
=\(\frac 12\)log2
Let \( f : (0, \infty) \to \mathbb{R} \) be a twice differentiable function. If for some \( a \neq 0 \), } \[ \int_0^a f(x) \, dx = f(a), \quad f(1) = 1, \quad f(16) = \frac{1}{8}, \quad \text{then } 16 - f^{-1}\left( \frac{1}{16} \right) \text{ is equal to:}\]

A ladder of fixed length \( h \) is to be placed along the wall such that it is free to move along the height of the wall.
Based upon the above information, answer the following questions:
(iii) (b) If the foot of the ladder, whose length is 5 m, is being pulled towards the wall such that the rate of decrease of distance \( y \) is \( 2 \, \text{m/s} \), then at what rate is the height on the wall \( x \) increasing when the foot of the ladder is 3 m away from the wall?