4.
\((1)\)三进制数\(121_{(3)}\)化为十进制数为_____\(.\)
\((2)\)若命题“\(∃x∈R\),使\(x^{2}+(a-1)x+1 < 0\)”是假命题,则实数\(a\)的取值范围为_____.
\((3)\)已知函数\(f(x)\)的导函数为\(f′(x)\),且满足\(f(x)=3x^{2}+2xf′(2)\),则\(f′(5)=\) _____.
\((4)\)以下五个关于圆锥曲线的命题中:其中真命题的序号为_____\((\)写出所有真命题的序号\()\)
\(①\)双曲线\( \dfrac{{x}^{2}}{16}- \dfrac{{y}^{2}}{9} =1\)与椭圆\( \dfrac{{x}^{2}}{49}+ \dfrac{{y}^{2}}{24} =1\)有相同的焦点;
\(②\)以抛物线的焦点弦\((\)过焦点的直线截抛物线所得的线段\()\)为直径的圆与抛物线的准线是相切的\(.\)
\(③\)设\(A\)、\(B\)为两个定点,\(k\)为常数,若\(|PA|-|PB|=k\),则动点\(P\)的轨迹为双曲线;
\(④\)过定圆\(C\)上一点\(A\)作圆的动弦\(AB\),\(O\)为原点,若\( \overset{→}{OP}= \dfrac{1}{2}\left( \overset{→}{OA}+ \overset{→}{OB}\right) \),则动点\(P\)的轨迹为椭圆\(.\)