7.
\((1)\int_{-\sqrt{2}}^{\sqrt{2}}{(\sqrt{2-{{x}^{2}}}})dx =\)
\((2)\)若\({{\left( 1+2x \right)}^{5}}={{a}_{0}}+{{a}_{1}}x+{{a}_{2}}{{x}^{2}}+{{a}_{3}}{{x}^{3}}+{{a}_{4}}{{x}^{4}}+{{a}_{5}}{{x}^{5}}\),则\({{a}_{1}}+{{a}_{3}}+{{a}_{5}}=\) .
\((3)\)已知\(f(x)\)为一次函数,且\(f(x)=x+2\int_{\ \ 0}^{\ 1}{f(t)dt}\),则\(f(x) =\)_______.
\((4)\)一个商人有一个\(40\)磅的砝码,由于跌落在地上而碎成\(4\)块\(.\)后来,称得每块碎片的重量都是整数磅,而且可以用这四块来称从\(1\)到\(40\)磅之间的任意整数磅的重物\(.\)问这四块砝码各自的重量可以是