# Writing math symbols.

#### STF92

##### New member
Hi: how do you write mathematical symbols here? I've seen other posts and they seem to use ASCII code but rendering special symbols.

#### Subhotosh Khan

##### Super Moderator
Staff member
Hi: how do you write mathematical symbols here? I've seen other posts and they seem to use ASCII code but rendering special symbols.

#### joshuaa

##### Junior Member
this is a latex expression

$$\displaystyle \frac{1}{x} =$$ \frac{1}{x}

#### Otis

##### Elite Member
… ASCII code but rendering special symbols.
Hi STF92. Suggestions for math symbols appear in the forum's posting guidelines. See the paragraph subheaded "Post the complete text of the exercise."

I often use ASCII characters because my keyboard has a numeric keypad; that allows me to type ALT-XXXX codes, for inserting many ASCII math characters. Alternatively, I use the Windows Character Map, to select, copy, and paste special characters. (Set the 'Group by' field to 'Unicode Subrange' and select 'Mathematical Operators' or other topics from the pop-up window.)

± × ÷ ∑ ∙ √ ∞ ∩ ≈ ≠ ≤ ≥ σ Ω α β θ º π Ψ

There's a link in the posting guidelines also for learning how to text expressions containing symbols. For examples, typing something like

root[3](625) $$\quad$$ means $$\quad \sqrt[3]{625}$$

sum[n=k,infty](x_n) $$\quad$$ means $$\quad \sum_{k}^{\infty} x_{n}$$

int[a,b](x^3 + 7x - 10) dx $$\quad$$ means $$\quad \int_{a}^{b} 3x^{3} + 7x - 10 \text{ dx}$$

For aligning columns (when typing a matrix, for example), you can use Code tags and a fixed-width font. (Click the 'Post Reply' button and then click the gear icon at the right end of the toolbar, to see my typing for the codes.)
Code:
-1   3  10   4
0  12   7  -2
0  -1   3   1