Questions & Answers of Frequency response

The impulse response of a system is h(t)=tu(t).For an input u(t-1) , the output is

For a periodic signal v(t)=30sin100t+10cos300t+6sin(500t+π/4), the fundamental frequency in rad/s is

A function is given f(t) = sin2t + cos2t. Which of the following is true?