# Functions Formulas     ## What are Functions?

IN mathematics, function typically describes the link between the input and the output. Function Formulas are basically used to find out the x-intercept, y-intercept and slope in any function. For a quadratic function, you can also compute its vertex using the function formula. Also, the function can be sketched out in a graphical representation for different values of x. The functions formula seems in the formula bar as f(x)= B2 + C2

### How to Solve Functions

The x-intercept of a function is computed by substituting the value of f(x) as zero (0).In the same manner, the y-intercept of a function is computed by substituting the value of x is zero (0). The slope of a linear function is typically identified by rearranging the equation to its standard form, f(x) = mx + c; Where, m = the slope.

We could also find out the vertex of a quadratic function by rearranging the equation to its standard form, f(x) = a(x – h)2 + k; where (h, k) represents the vertex.

### Functions And Linear Equations

If we in the given equation y = x+3 allot a value to x, the equation will provide us with a value for y. For Example,

y = x + 3

If x = 5, then

y = 5 + 3 = 8

### Using Functions

There are a wide variety of functions in algebraic mathematics. Here are some of the functions we most commonly use:

1. SUM: This function sums up all the values of the cells in the argument.

2. COUNT: This function is used to count the number of cells having numerical data in the argument. This function is apt for counting items in a cell range quickly.

3. AVERAGE: This function identifies the average of the values involved in the argument. It computes the sum of the cells and then specifically divides that value by the number of cells in the argument.

4. MIN: This function identifies the lowest cell value involved in the argument.

5. MAX: This function identifies the greatest cell value involved in the argument.

6. SQRT: It identifies the square root of the value in cell D10. For example SQRT (D10)

7. TODAY: It gets back to the current date (leaving the parentheses empty). For example, TODAY ()

### Solved Examples Using Functions Formulas

Example: Find out the slope, x-intercept and y-intercept of a linear equation, with the values given as f(x) = 6x + 5.

Solution:

Given,

f(x) = 6x + 5

The standard form of a linear equation is as given:

f(x) = mx + c

Thus,

Slope = m = 6

Now, Substitute f(x) = 0,

0 = 6x + 5

6x = -5

x = −5/6

The x-intercept is (−5/6, 0)

Now, Substituting x = 0,

f(x) = 6(0) + 5

f(x) = 0 + 5

f(x) = 5

The y-intercept is (0, 5).

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