The picture shows graphs of two quadratic functions \( f_1(x) \) and \( f_2(x) \). Find the unknown real positive constant \( a \) (as shown in the picture) such that the value of the definite integral \( \int\limits_{-1}^1 f_1(x)\,\mathrm{d}x \) is greater by \( 8 \) than the value of the definite integral \( \int\limits_{-1}^1 f_2(x)\,\mathrm{d}x \).
Any positive real number \(x\) can be written as \(x=c+d\), where \(c\) is an integer and \(d\in[ \left. 0,1\right)\). Then \(c\) is called the integer part of \(x\) and is denoted by \(\left[x\right]\). Evaluate the following definite integral.
\[\int\limits_{\frac52}^{2.8}\left[x\right]\,\mathrm{d}x \]
Any positive real number \(x\) can be written as \(x=c+d\), where \(c\) is an integer and \(d\in[ 0,1 )\). Then \(c\) is called the integer part of \(x\) and is denoted by \(\left[x\right]\). Evaluate the following definite integral.
\[\int\limits_{3.1}^{\frac72}\left[x\right]\mathrm{d}x \]
Let \(\mathrm{sgn}(x) = \begin{cases}
1, & x > 0 \\
0, & x = 0.\\
-1, & x < 0\end{cases}\) Evaluate the following definite integral.
\[\int\limits_{-2}^{-1}\left(\mathrm{sgn}(x-1)+1\right)\, \mathrm{d}x \]
Let \(\mathrm{sgn}(x) = \begin{cases}
1, & x > 0 \\
0, & x = 0.\\
-1, & x < 0\end{cases}\) Evaluate the following definite integral.
\[\int\limits_{-3}^{-2}\left(\mathrm{sgn}(x+1)-1\right)\, \mathrm{d}x \]