Question 13, 1 less than or equal to a 1 less than or equal to a2 less than or equal to a3 less than or equal to a4 less than or equal to a5 less than or equal to a6 less than or equal to a7.

According to the meaning of the question, a3 is a 1 times q, a5 is the square of a 1 times q, a7 is the cube of a 1 times q, a4 is a2 plus 1, and a6 is a2 plus 2.

Because q is the smallest, a 1=a2= 1, so q is greater than or equal to 1, the square of q is greater than or equal to 2, and the cube of q is greater than or equal to 3.

So the minimum q is the third power of 1/3.

Problem 14, that is, the area between two straight lines intersects with a circle.