刚碰微积分,还很菜,有两三道题想要各位大侠帮忙解答、讲解,最好跟我说说分别涉及的是什么知识点。谢啦!!
1) 求出 x e^x的不定积分:
A. (x2/2)e^x + x e^x
B. x e^x + e^x
C. x e^x - e^x
D. (x2/2)e^x
2) Find the volume of the solid formed by revolving the region bounded by y = x^2 and the lines y = 1 and x = 2 about the line y = 1. (求出被函数y=x^2、直线y=1和x=2围绕的区域绕直线y=1旋转后的体积)
A. (38/15)pi
B. (4/3)pi
C. (7/3)pi
D. (31/5)pi
3. Sum the infinite series 2 - 1 + (1/2) - (1/4) + (1/8) - (1/16) + (1/32) - (1/64) + ... (计算这个无穷级数的和)
A. Diverges
B. 4/3
C. 4