单项选择题
已知,则f(x)在(0,π)内的正弦级数bnsinnx的和函数S(x)在x=π/2处的值及系数b3分别为:()
A.S(π/2)=1/2,b3=2/3π B.S(π/2)=1,b3=1/3π C.S(π/2)=1,b3=2/3π D.S(π/2)=1/2,b3=1/3π
A.π B.1/10π(-1+) C.1/10π(1+) D.1/10π(1-)
A.ln(1-x) B.ln[1/(1-x)] C.ln(x-1) D.-ln(x-1)