Showing posts with label Solving Equations. Show all posts
Showing posts with label Solving Equations. Show all posts

Monday, October 29, 2012

Solving Equations with Radicals and Exponents

Solving equations with radicals and exponents:

Exponents:      

The term exponent in math is used to find the exponential value of the particular value it may be integer  or fraction . We can easy to get  the power of a  number using online calculator ,Consider  the unknown number , Here x is base and y is the power  of x . Let us consider the  number 23 Here 2 is the base(x)  and 3 is the power of 2(y). We calculate  23= 2 x 2 x 2 =8

Radicals:

Square root of the number is said to be a radical number .A radical equation is an equation in which a variable is under a radical term.Let us discuss about the solving an equations with radical and  exponents,

Example Problems to Solving Equations with Radicals and Exponents:

Example 1: Solve `sqrt(3x^2 +8x)` -3 =0

Solution:

Given `sqrt(3x^2+8x)` -3=0

isolate the radical equation,

`sqrt(3x^2 +8x)=3`

Take square on both sides we get,

`(sqrt3x^2+8x)^2` `=3^2`

3x^2+8x=9

3x^2+8x-9 =0

now you can solve the above equation using factoring method,

Using quadratic formula ,

x= `(-b+-sqrt(b^2-4ac))/(2a)`

Here b=8 ,a=3 and c=-9

Therefore ,

x= `(-8+-sqrt(8^2-(4)(3)(-9)))/(2(3))`

`=(-8+-sqrt(64+108))/6`

`=(-8+-sqrt(172))/6`

`=(-8+-sqrt(2*2*43))/6`

`=(-8+-2sqrt(43))/6`

`=2([-4+-sqrt(43)])/6`

`=(-4+-sqrt43)/3`

Therefore,

The factors are , `(-4+sqrt43)/3` ,`(-4-sqrt43)/3`

Example 2 : Solve `sqrt( x^2 +5x)-3=0`

Solution:

Isolate the given radical and exponent equation, we get,

`sqrt(x^2+5x)=3`

Take square root on both sides we get,

x^2+5x=32

x^2+5x=9

x^2+5x-9=0

Above equation in the form of ax^2+bx+c.

Therefore  you can find the factors using quadratic formula,

`x= (-b+-sqrt(b^2-4ac))/(2a)`

Here , b=5,a=1 and c=-9

substitute these values into formula,

`x= ((-5+-sqrt(5^2-4(1)(-9)))/(2(1)))`

`=(-5+-sqrt(25+36))/2`

`=(-5+-sqrt(61))/2`

`=(-5+-sqrt(61))/2`

Therefore ,

The factors are ,

`x= (-5+sqrt61)/2`    ,   `(-5-sqrt61)/2`

More about the Solving of Equations with Radicals and Exponents:

Example3: Solve `sqrt(2x^2+4)=4`

Solution:

Take square on both sides we get,

`(sqrt(2x^2+4))^2` =42

2x^2+4 =16

subtract both sides by 4,we get

2x^2+4-4=16-4

2x^2=12

Divide both sides by 2 ,

x^2 =`12/2`

x^2=6

x=`sqrt6`

Example 4: Solve the equations with radicals  and exponents `sqrt(4x^2+8)=11`

Solution:

Take square on both sides , we get,

4x^2+8 =121

Subtract both sides by 8 we get,

4x^2+8-8 =121-8

4x^2=113

Divide both side by 4,

x^2 =113/4

x=`sqrt(113/4)`

x=`(sqrt113)/2`

Therefore the value of `x= sqrt113/2`

Example 5: Solve the equation with radicals and exponents `sqrt(6x^2+7)` `=8`

Solution:

Take square on both sides we get,

6x^2 +7 = 64

Subtract both side by7,

6x^2+7-7=64-7

6x^2=57

Divide both side by 6,

x^2 =`57/6`

x= `sqrt(57/6)`

Therefore the value of `x = sqrt(57/6)`