Refer to the op amp circuit shown below.
Let R_{1} = 140 k_, R_{2} = 10 k_, R_{3} = 10 k_, R_{4} = 20 k_, RL = 10 k_. Assume the op amp is ideal.Find the equation relating the output voltage vo(t) if the input voltage source isvI(t) = 1V cos(2∏10^{3}t).Sketch v_{o}(t).