Sub-heading: 11 Selected Math Questions and Answers (2020 Free Edition)
Introduction: This article will bring you carefully selected 11 math questions, with a detailed analysis of the answers. These questions are suitable for students of all levels to self-test, let’s improve our math ability in the process of solving problems! The content of this article is free and open, and everyone is welcome to read, practice and share.
1. Fill in the blanks
1. If the equation of a circle is known to be x^2+y^2=4, then the coordinates of its center are _______.
Answer: (0,0)
Analysis: According to the standard equation of the circle x^2+y^2=r^2, it can be seen that the coordinates of the center of the circle are (0,0) and the radius is 2.
2. Multiple choice questions
2. Let the range of the function f(x)=sinx+cosx be _______.
A.[-√2,√2]B.[-√5/2,√5/2]C.[-√3/2,√3/2]D.[-√3,√3]Sweet Bonanza 1000
Answer: A
Analysis: Using the properties of trigonometric functions, the range of f(x) can be obtained by formula transformation as [-√2,√2].
3. Answer questions
3nổ hũ đổi thưởng. If we know that the number series {an} is an equal difference series, and a_1=3, a_5=15, find the first n terms and Sn of the number series.
Answer: Let the tolerance of the series be d, according to the nature of the equal difference series, there are a_5=a_1+4d, and the solution is d=3. The expression of Sn is obtained by using the formula Sn=n/2(a_1+a_n) of the sum of the first n terms of the equal difference series.
Fourth, the application of the problem
4. A shopping mall conducts promotional activities, and a lottery can be drawn if you purchase more than 100 yuan. The rules of the draw are as follows: there are 4 red balls and 6 white balls in an opaque box, and the customer touches one of the balls, and if he touches the red ball, he wins the first prize. Find the probability of winning the first prize P(A).Vận May Cá Vược Lớn
Answer: Assuming that the probability of touching the red ball is P(A), since there are 4 red balls and 6 white balls in the box, a total of 10 balls, so P(A) = number of red balls / total number of balls = 4/10 = 0.4 or 40%.
5. Trigonometric function questions
5. If sinα+cosα=√3/3, find the value of sinα-cosα.
Answer: Solve the problem after the square of both sides according to the known conditions, and pay attention to the simplification using the basic properties of trigonometric functions.
Questions 6-11 (omitted)…
Conclusion: This article presents a total of 11 math problems, including basic questions and difficult problems, and analyzes some of them in detail. I hope that through the practice of these topics, everyone can consolidate their knowledge and improve their ability. Welcome everyone to leave a message in the comment area to discuss, share solution ideas, and make progress together! The content of this article will continue to be updated for free, so stay tuned.
