Refer to wiki: Significant figures
Refer to Khan academy: Intro to significant figures

Refer to math is fun: Cross Sections (Geometry)

Cross sections is a interesting geometry problem, it let you thinks about how to slice a 3D solid shape into some 2D shapes, for instance:

• Slice a cube into:

Refer to math is fun: Parabola : The graph for quadratic

Parabola is a quadratic's graph.

Refer to khan academy: Compound inequalities

Means an inequality that combines two simple inequalities, 
and our mission is to find out the solution of the compound inequality.

Refer to Maths is fun.

Refer to khan academy: Convert Repeating decimal to fraction

There’re some repeating decimals or recurring decimals, it's way more easier to write down with a fraction.

To play with trapezoid, Refer to GeoGebra

Trapezoid

• Scalene trapezoid: No equal sides.
• Isosceles trapezoid: Two legs are equal.

Refer to Wiki: Dimensional analysis

For example, convert 60 km/h to 60000 m/h, or to 1 km/minute.
It works out many problem in physical science and engineering problems.

▶ Jump forward to the note on application on Partial fractions for Calculus Integration.

Example

Solve:

• Factorize the dominator.

Refer to khan academy: Point-slope form of linear equation

We all know the slope-intersect form of a linear equation is y = mx + c, which m is the slope of line, c is the constant represent the y-intersect of the line.
And we can convert it…

• Slope-intersect form:

y = mx + b, which m as slope, b as y-intersect.
This form is good for graphing a line with y-intersect and a certain slope.

• Slope-point form: