f(t)dt= f(x)dx 从而」。(x)=(x)+x PJf(x)dx (2)若为f(x)奇函数,则有f(x)f(-x) 则dx=-dt,且 f(x)dhx=f(-1)d(-1) 从而」f(x)k=-J/(x)+/(x)d=09 从而 0 0 ( ) ( ) ( ) a a a a f x dx f x dx f x dx − = +    0 0 ( ) ( ) a a = − = f t dt f x dx   (2)若为ƒ(x)奇函数, 则有ƒ(x)=−ƒ(− x) 令x = −t, 则 d x = −d t, 且 0 0 ( ) ( ) ( ) a a f x dx f t d t − = − −   0 0 ( ) ( ) a a = = − f t dt f x dx   从而 0 0 ( ) ( ) ( ) 0 a a a a f x dx f x dx f x dx − = − + =    0 2 ( ) a = f x dx 