三角函数的读法：sin = sinecos = cosinetan = tg = tangentcot = ctg = cotangentsec = secandcsc = cosecand微分 dx：d x (安字母读)导数 y‘,dy/dxy' ：y 撇,y primedy/dx ：d y d x (按字母读),y对x求导,y的导数...