Questions number 19 and 20 are Assertion – Reason based questions of 1 mark each. Two statements are given – one labelled Assertion (A) and other…

Questions number $\displaystyle 19$ and $\displaystyle 20$ are Assertion – Reason based questions of $\displaystyle 1$ mark each. Two statements are given – one labelled Assertion (A) and other labelled Reason (R). Select the correct answer to these questions from the codes (A), (B), (C) and (D) as given below : Assertion (A): The area of the region bounded by the line $\displaystyle \mathrm{y}-1=x$, the $\displaystyle x$-axis and the ordinates $\displaystyle x=-1$ and $\displaystyle x=1$ is $\displaystyle 2$ square units. Reason (R): The area of the region bounded by the curve $\displaystyle \mathrm{y}=\mathrm{f}(x)$, the $\displaystyle x$-axis and the ordinates $\displaystyle x=\mathrm{a}$ and $\displaystyle x=\mathrm{b}$ is given by $$\int_{\mathrm{a}}^{\mathrm{b}} \mathrm{f}(x) \mathrm{d} x . $$