1.
设椭圆\(C\):\( \dfrac {x^{2}}{a^{2}}+ \dfrac {y^{2}}{b^{2}}=1(a > b > 0)\)的离心率为\(e= \dfrac { \sqrt {2}}{2}\),点\(A\)是椭圆上的一点,且点\(A\)到椭圆\(C\)两焦点的距离之和为\(4\).
\((1)\)求椭圆\(C\)的方程;
\((2)\)椭圆\(C\)上一动点\(P(x_{0},y_{0})\)关于直线\(y=2x\)的对称点为\(P_{1}(x_{1},y_{1})\),求\(3x_{1}-4y_{1}\)的取值范围.