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Please help this is pre calculus

Please help this is pre calculus-example-1
User Marcos Cassaro
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1 Answer

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Explanation:

1. First things first, the binomial tells us the zeroes.


- (x - 2) {}^(2) = 0


(x - 2) {}^(2) = 0


x - 2 = 0


x = 2

This root has a multiplicity of 2, so this root will "bounces off the x axis"


(x + 4) = 0


x = - 4

Our x intercepts are

2 and -4

This root has a multiplicty of 1, so it will cross thorough the x axis.

Our leading degree is odd and we have a negative leading coefficient so

as x approaches ♾️, f(x) approaches negative ♾️

and as x approaches negative ♾️, f(x) approaches ♾️.

Our y intercept can be found by letting x=0,

so


- (0 - 2) {}^(2) (0 + 4) = - ( - 2) {}^(2) (0 + 4) = - (4)(4) = - 16

So our y intercept is -16.

For Rational Functions, if the numerator and denominator share the same factor they are considered a removable discontinuity or hole.

Set it equal to 0.


x + 5 = 0


x = - 5

So we have a hole at x=-5.

Next, simplify the fraction.


(x - 4)/(x - 6)

Now, plug in -5


( - 5 - 4)/( - 5 - 6) = ( - 9)/( - 11) = (9)/(11)

So we have a hole at (-5,9/11).

To find y intercept, let x=0,


(0 - 4)/(0 - 6) = (2)/(3)

To find Vertical Asymptote, set denominator equal to 0


x - 6 = 0


x = 6

Draw a vertical dotted line at x=6

To find HA, this is the only case since the numerator and denominator has the same degree.

So using the leading coefficients, divide the numerator leading coefficient/ denominator leading coefficient.

The leading coefficient for both is 1 so


ha = (1)/(1)

So our HA is y=1.

Draw a horizon tal dotted line at y=1

We have no slope asymptote.

The graph is above.

Part 3:

(3x-1)(2x+1)>0


3x - 1 = 0


3x = 1


x = (1)/(3)


2x + 1 = 0


2x = - 1


x = - (1)/(2)

We have three possible regions, when x is positive

  • When x is less than -1/2
  • When x lies between -1/2 and 1/3
  • When x is greater than 1/3

Pick a random number less than -1/2 and plug it in the inequality to see if it true.

Let use -1


(3( - 1) - 1)(2( - 1) + 1) = ( - 4)( - 1) = 4

Since 4>0, Whenever x is less than -1/2, the function is positive (greater than zero)

Let's try the next region.

Let use 0


(3(0) - 1)(2(0) + 1) = ( - 1)(1) = - 1

So this solution won't work

Let try the next region, let use 1.


(3(1) - 1)(2(1) + 1) = (2)(3) = 6

Since 6>0, Whenever x is greater than 1/3, the function is positive(greater than zero).

Our answer is

(-oo,-1/2) U (1/3,oo).

Part 4:

We know x cannot be -2 because


x + 2 = 0


x = - 2

So -2 can not be in our answer.


(x - 1)/(x + 2) \leqslant 2


x - 1 \leqslant 2(x + 2)


x - 1 \leqslant 2x + 4


- 5 \leqslant x

So


x \geqslant - 5

However x can not be -2. so we say

[-5,-2) U (-2,oo)

Please help this is pre calculus-example-1
Please help this is pre calculus-example-2
User Zasuk
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