Numbers and Beyond numbers: December 2021

Friday, December 17, 2021

SAT Subject Math 1 Practice Diary

12/17/2021 SAT Practice Diary

Finish eight pracices. Over 80% is kind of linear equation in all sorts of disguise.

multiple choices 对解题有很大的帮助。这道题我先算成 79/200, should be 79 / 164, 164 = 200 - 15-31.

11/5/2021 SAT Subject Math 1 Practice Diary

Abandon preparation for AP computer test ( principle and Java)
Studying NES 203 (middle school math)
Dong SAT Math Subject 1 practice

https://sharonwumathbeyondnumbers.blogspot.com/2021/11/the-official-sat-subject-test-study_5.html

*****Question 2: 我怎么没有想 Arithematic sequence 是线性 linear equation.

11/7/2021

Officical Practic 1

注意raw score 不是做对题的数目，要减去错的题数 ×0.25。做对38道题，做错12道题。

38 － 12 ×0.25 = 35, 分数650. 。几乎都是粗心。也是很久不做题了。

Officical Practic 2

做对45道题，做错5道题。

45 － 5×0.25 = 44, 分数740。是粗心。

Officical Practic 3

做对46道题，做错4道题。

46 － 4×0.25 = 45, 分数750。

Officical Practic 4

做对47道题，做错3道题。

47 － 3×0.25 = 46, 分数770。

11/13/2021

Kaplan SAT Subject Test Mathematics Level 1 : 2015-2016

*****https://www.blogger.com/blog/post/edit/393815941779271630/8323001634422917541

i and (-i), see Q38

Errors: Q18, 35, 42, 46, 49. 做对45道题，做错5道题

45 － 5×0.25 = 44, 分数730。

11/24/2021

线性方程人人会解。这是在考阅读理解还是线性方程？所以，学生数学差是两方面的，literature and math

Wednesday, December 15, 2021

Exponential function, geometric series

Exponential function, geometric series, 2, 4, 8, 16, y = 2x 指数函数, 等比级数

arithmetic series. 等差级数 2 + 2 + 2 + 2, y = ax + b, y = 2x + 2，线性方程

Use Calculator to solve the problem

我想AVERY如何解题。最后想到可以 Calculator 用解题。

Line, Tanget line, derivative

https://www.khanacademy.org/math/ap-calculus-ab/ab-differentiation-1-new/ab-2-1/v/derivative-as-slope-of-tangent-line

A tangent line is a straight line that touches a function at only one point. ... The tangent line represents the instantaneous rate of change of the function at that one point. The slope of the tangent line at a point on the function is equal to the derivative of the function at the same point

https://clas.sa.ucsb.edu/staff/lee/secant,%20tangent,%20and%20derivatives.htm

When I think of a tangent line, I am kind of overthinking. I didn't notice y = c, it must be a horizontal line. So I try to draw a tangent line at any point. It is difficult. Then, I notice it is y = c. Everything becomes easy.

如果想成直线该如何做

Why do equations have many forms?

不同的格式有不同的意思。线性方程最明显。

For a quadratic equation ax2+bx+c = 0,

the sum of its roots = –b/a and the product of its roots = c/a.

A quadratic equation may be expressed as a product of two binomials.

(x-a)(x-b) = 0

This method is called factoring.

A monomial is an algebraic expression with only one term in it. Example: x3, 2x, y2, 3xyz etc.

A polynomial is an algebraic expression with more than one term in it. Alternatively, it can be stated as – polynomial is formed by adding/subtracting multiple monomials. Example: x3+2y2+6x+10, 3x2+2x-1, 7y-2 etc. A polynomial that contains two terms is called a binomial expression. A polynomial that contains three terms is called a trinomial expression.

(x- D) 2+ A

(x-B1) ( x-B2) factoring

Ax2 + bx + C