An equation is a statement that connects two expressions with an $=$ sign and asserts their equality. An identity is an equation that holds for every variable tuple for which the equation is defined: $\log(xy)\equiv \log(x)+\log(y)$ A conditional equation holds for some variable tuple(s):

2013年5月28日 · Stack Exchange Network. Stack Exchange network consists of 183 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

I'm wondering if there is a symbol or notation for Round to the nearest 10th For example, the area of a circle with a radius of 45 feet, rounded to the nearest square foot, could be written as, A =...

2011年10月2日 · If the equations of the diagonals of the rectangle are Ax + By + C = 0 and Dx + Ey + F = 0 then an equation for the rectangle is: M|Ax + By + C| + N|Dx + Ey + F| = 1. M and N can be found by substituting the coordinates of two adjacent vertices of the rectangle. In fact, this equation can be used to describe any parallelogram.

2017年4月20日 · Now we are looking for the equation of a circle through the origin and two other points, which is of the form $$(x-x_c)^2+(y-y_c)^2-r^2=x^2-2xx_c+y^2-2yy_c=0,$$ as there is no independent term. This results in the $2\times2$ linear system of equations

The equation of an object is a way of telling whether a point is part of an object -- if you substitute the coordinates of the point into the equation and the equation is true, then the point is on the object; if the equation is not true for that point, then the point is not on the object.

Now you may now see how the equation for a circle arises-- it's just the graph of $\pm\sqrt{a^2-(r-c)^2}=z$. Variable c is the length from the origin to the center of the circle while a is the radius of the circle. Now we can expand this into three dimension by replacing the r with $\sqrt{x^2+y^2}$. By then you have two parameters

Equation means equality. They are both related to the word equal . If such an equality is true for all values of the variable , it is called an identity , e.g., $\sin^2x+\cos^2x=1$ is true for all x .

2014年1月14日 · For the case of the Mobius strip we have that \begin{equation} p(t) = (R \cos t, R \sin t, 0). \end{equation} By substitution of the origin and direction vectors into the surface (2) we arrive to the same parametric equations(1.2) for the Mobius band.

2013年6月22日 · Using the "pins and string" definition of an ellipse, which is described here, its equation is $$ \Vert\mathbf x - (\mathbf x_0 + c \mathbf u)\Vert + \Vert\mathbf x - (\mathbf x_0 - c \mathbf u)\Vert = \text{constant} $$ This is equivalent to the one given by rschwieb. If you plug $\mathbf u = (\cos\alpha, \sin\alpha)$ into this, and expand ...