Tuesday, November 27

Solving Basic Exponential Function


Introduction:

Exponential function can be represented as f(x) = bx where b is real number and x is a variable. Domain of any function f(x) is a set of all real values on X-axis for which function is defined and exponential function is defined for all real value of x on X-axis so domain of exponential function is all real number. For function f(x) = bx value of f(x) will be always positive if b is positive and always negative if b is negative so in range of function there will no negative number if b is positive and there will be no positive number in range of function f(x) if a is negative. Exponential functions will be strictly increasing or strictly decreasing depending on value of b. If b >1 then function will be strictly increasing and if b < 1 function will be strictly decreasing for example function y=5x is strictly increasing and function y = (1/5) x is strictly decreasing function. Inverse of exponential function is logarithmic function, logarithmic function can be written as y = logxy where x and y both are positive numbers. Exponential function can also be written as y =ex where e is a real number.



More on Exponential Functions:
For exponential function f(x) = bx , b is called base of exponential function. If two equal exponential functions have same base then their power will be also same for example if bx = by then we can write as x = y, to find inverse of exponential function just inverse the position of x and y in function.Looking out for more help on college algebra solver in algebra by visiting listed websites.

Basic properties of exponential functions:

`e^x e^y = e^(x+y)`
`(e^x)^p = e^(px)`
`de^x/dx = e^x`
`de^(ax)/dx = ae^(ax)`
`d^n e^(ax)/dx^n = a^n e^(ax)`
`e^x/e^y = e^(x-y)`

Example Problem:

Example 1: What will be value of x if 2x = 8?

Solution: 2x = 8

2x = 23

Base is same for both side of equation so

x = 3

Example 2: Find inverse of exponential function y = 5x

Solution: Given function is y = 5x

To find inverse of this function substitute y for x and x for y

x = 5y

log5 x = log5 5y

= y log5 5

= y

So, Inverse of given function is y = log5 x

Example 3: Find the exponential function y = 7x and also graph the function.

Solution: A set of ordered pairs for the equation is shown below.

Putting the value x = -0.5 we get

`y = 7^-0.5`

= 0.3779

(x,y) = (-0.5, 0.3779)

Putting the value x = -0.25 we get

`y = 7^-0.25`

= 0.614

(x,y) = (-0.25, 0.614)

Putting the value x = 0 we get

`y = 7^0`

= 1

(x,y) = (0,1)

Putting the value x = 0.25 we get

`y = 7^0.25`

= 1.626

(x,y) = (0.25, 1.626)

Plotting the given points to get the graph of the exponential function,



This graph shows the part of the exponential function between the co-ordinate points. So, it might not look like a curve but if we plot all the points over the real domain, we get the exact curve.

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