With the end of the 20 17 college entrance examination mathematics subject, what parents and candidates want to know most is nothing more than the answers to the college entrance examination mathematics questions. Below, I will provide you with the test questions and answers of two volumes of the national college entrance examination mathematics volume for parents and students' reference. I wish the college entrance examination students good results this year.

1 1. Randomly draw 1 card from five cards with 1, 2, 3, 4 and 5 written on them, and then randomly draw 1 card after putting it back, so the probability that the number on the first card is greater than the number on the second card is

a . 1/ 10 b . 1/5 c . 3/ 10d . 2/5

The answer to this question is D.

13. The maximum value of the function f(x)=2cosx+sinx is.

The answer to this question is the root number five.

15. The length, width and height of a cuboid are 3, 2 and 1 respectively, and their vertices are all on the spherical surface of the ball O, so the surface area of the ball O is

The answer to this question is 14π.

16. The opposite sides of the internal angles A, B and C of △ A, B and C are A, B and C respectively. If 2bcosB= acosc+cccosa, then B=

The answer to this question is π/3.

17.( 12 points)

It is known that the sum of the first n terms of arithmetic progression {an} is Sn, and the sum of the first n terms of geometric progression {bn} is t n, a 1=- 1, b 1= 1, and a3+b2=2.

(1) If a3+b2=5, find the general formula of {bn};

(2) If T=2 1, find S 1.

The above are some questions and answers in the second volume of the national college entrance examination for liberal arts mathematics, for reference only.