化二次积分为极坐标系下的二次积分,f(x,y)dy的值是:()
A:f(rcosθrsinθ)rdr
B:f(rcosθ,rsinθ)rdr
C:f(rcosθrsinθ)rdr
D:f(rcosθ,rsinθ)rdr
出自:专业知识