97. Let's calculate the area of the figure bounded by the lines

$$
y=1, y=0, y=\log _{2} x \text { and } x=0
$$
Solution. Apply symmetry with respect to the line $y=x$ (Fig. 48); the image of the given figure will be a curvilinear trapezoid bounded by the lines $y=2^{x}, y=0, x=0$ and $x=1$, hence, by formula (1)

$$
S=\int_{0}^{1} 2^{x} d x=\frac{1}{\ln 2}
$$