1. Which of these is true for all f (a)? Off (ae) dac = - So f (ac) dac Of k f (x) dac = f (k) So f (z) da Ofof ( x) dac + fd f (ac ) dac = Said f (2) doc Of " a f (2) dac = 0 O S f (a) g (2) dac = So f (ze) dae . So g (ac) dac 2. Given S_? f (x) dx = 11, S_5 f (x) dx = 20 Find S_3 f (x) dx O -9 O -20 O 7 O -15 O 2