gibsonj338

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 #1
avatar+1904 
0

To answer the first queston, first factor the polynomial function.

 

\(y={x}^{3}-{3x}^{2}+16x-48\)

 

\(y=({x}^{3}-{3x}^{2})+(16x-48)\)

 

\(y={x}^{2}(x-3)+(16x-48)\)

 

\(y={x}^{2}(x-3)+16(x-3)\)

 

\(y=({x}^{2}+16)\times(x-3)\)

 

\(y=({x}^{2}+{4}^{2})\times(x-3)\)

 

\(y=(x-4)\times(x+4)\times(x-3)\)

 

Now set each x value to zero and solve

 

\(x-4=0\)

 

\(x-4+4=0+4\)

 

\(x-0=0+4\)

 

\(x=0+4\)

 

\(x=4\)

 

\(x+4=0\)

 

\(x+4-4=0-4\)

 

\(x+0=0-4\)

 

\(x=0-4\)

 

\(x=-4\)

 

\(x-3=0\)

 

\(x-3+3=0+3\)

 

\(x-0=0+3\)

 

\(x=0+3\)

 

\(x=3\)

 

Now plug each answer to the original polynomial function to see if the answers will fit in the original polynomial function.

 

\(y={x}^{3}-{3x}^{2}+16x-48\)

 

\(0={x}^{3}-{3x}^{2}+16x-48\)

 

\(0={4}^{3}-3({4}^{2})+16(4)-48\)

 

\(0=64-3({4}^{2})+16(4)-48\)

 

\(0=64-3(16)+16(4)-48\)

 

\(0=64-48+16(4)-48\)

 

\(0=64-48+64-48\)

 

\(0=16+64-48\)

 

\(0=80-48\)

 

\(0≠32\)

 

\(y={x}^{3}-{3x}^{2}+16x-48\)

 

\(0={x}^{3}-{3x}^{2}+16x-48\)

 

\(0={(-4)}^{3}-{3(-4)}^{2}+16(-4)-48\)

 

\(0=-64-{3(-4)}^{2}+16(-4)-48\)

 

\(0=-64-3(16)+16(-4)-48\)

 

\(0=-64-48+16(-4)-48\)

 

\(0=-64-48+(-64)-48\)

 

\(0=-112+(-64)-48\)

 

\(0=-176-48\)

 

\(0≠-224\)

 

\(y={x}^{3}-{3x}^{2}+16x-48\)

 

\(0={x}^{3}-{3x}^{2}+16x-48\)

 

\(0={3}^{3}-{3(3}^{2})+16(3)-48\)

 

\(0=27-{3(3}^{2})+16(3)-48\)

 

\(0=27-3(9)+16(3)-48\)

 

\(0=27-27+16(3)-48\)

 

\(0=27-27+48-48\)

 

\(0=0+48-48\)

 

\(0=48-48\)

 

\(0=0\)

 

The only real answer is x=3.  Becasue x=4 and x=-4 are not real answers, that means they are imaginary answers.  This means that B is the correct answer.

 

I know how to solve the second question but, because I do not know how to type it out on this forum, I will leave that to someone who does know how to answer the question and how to type it out on this forum.

Aug 15, 2017
 #1
avatar+1904 
0

Polar coordiantes can be represented as (r, θ) where r equals the radius and θ equals the angle in degrees or in radians.  To convert the cartesian coordinate (2,-2) to polar coordinate, first figure out what r is. To find out what r is, use the formula known as pythagoras theorem: \({r}^{2}={x}^{2}+{y}^{2}\) where x is the x-coordinate and y is the y-coordinate.

 

\({r}^{2}={x}^{2}+{y}^{2}\)

 

\({r}^{2}={2}^{2}+{(-2)}^{2}\)

 

\({r}^{2}=4+{(-2)}^{2}\)

 

\({r}^{2}=4+4\)

 

\({r}^{2}=8\)

 

\(\sqrt{{r}^{2}}=\sqrt{8}\)

 

\(r=\sqrt{8}\)

 

\(r=2\sqrt{2}\)

 

Now figure out what θ is.  To figure out what θ is, use the formula known as tangent function:

\(tan(\Theta)=\frac{x}{y}\).

 

\(tan(\Theta)=\frac{x}{y}\)

 

\(tan(\Theta)=\frac{2}{-2}\)

 

\(tan(\Theta)=-\frac{2}{2}\)

 

\(tan(\Theta)=-1\)

 

\({tan}^{-1}(tan(\Theta))={tan}^{-1}(-1)\)

 

\(\Theta ={tan}^{-1}(-1)\)

 

\(\Theta =-45°\)or \(\Theta =-\frac{\pi}{4}\)

 

Because the question asks to be within the 0° ≤ θ < 360° parameter, ignore the radian answer above.  Since the degree answer is not within the 0° ≤ θ < 360° parameter, you need to change the answer to an equilivent answer that fits the 0° ≤ θ < 360°.  To do that add 360° to the degree answer.

 

\(\Theta=-45°+360°\)

 

\(\Theta=315°\)

 

Now put r and θ in polar cordinate form.

 

\((r,\Theta)\)

 

\((2\sqrt{2}, 315°)\)

 

To find another coordinate in polar form that is the same as the polar coordinate above that fits the 0° ≤ θ < 360°, first subtract 180° from 315°.

 

\(\Theta=315°-180°\)

 

\(\Theta=135°\)

 

Second, change \(2\sqrt{2}\) to \(-2\sqrt{2}\).

 

Now put r and θ in polar cordinate form.

 

\((r,\Theta)\)

 

\((-2\sqrt{2},135°)\)

.
Aug 11, 2017
 #1
avatar+1904 
+1

I do not know how to solve the second problem; however, I can help solve the first problem.  To solve the first problem, use Heron's Formula.

 

\(A=\sqrt{\frac{a+b+c}{2}\times(\frac{a+b+c}{2}-a)\times(\frac{a+b+c}{2}-b)\times(\frac{a+b+c}{2}-c)}\)

 

A = Area

a = side a or \(\frac{4}{3}\)

b = side b or \(2\)

c = side c or \(\frac{8}{3}\)

 

\(A=\sqrt{\frac{\frac{4}{3}+2+\frac{8}{3}}{2}\times(\frac{\frac{4}{3}+2+\frac{8}{3}}{2}-\frac{4}{3})\times(\frac{\frac{4}{3}+2+\frac{8}{3}}{2}-2)\times(\frac{\frac{4}{3}+2+\frac{8}{3}}{2}-\frac{8}{3})}\)

 

\(A=\sqrt{\frac{\frac{4}{3}+\frac{6}{3}+\frac{8}{3}}{2}\times(\frac{\frac{4}{3}+2+\frac{8}{3}}{2}-\frac{4}{3})\times(\frac{\frac{4}{3}+2+\frac{8}{3}}{2}-2)\times(\frac{\frac{4}{3}+2+\frac{8}{3}}{2}-\frac{8}{3})}\)

 

\(A=\sqrt{\frac{\frac{10}{3}+\frac{8}{3}}{2}\times(\frac{\frac{4}{3}+2+\frac{8}{3}}{2}-\frac{4}{3})\times(\frac{\frac{4}{3}+2+\frac{8}{3}}{2}-2)\times(\frac{\frac{4}{3}+2+\frac{8}{3}}{2}-\frac{8}{3})}\)

 

\(A=\sqrt{\frac{\frac{18}{3}}{2}\times(\frac{\frac{4}{3}+2+\frac{8}{3}}{2}-\frac{4}{3})\times(\frac{\frac{4}{3}+2+\frac{8}{3}}{2}-2)\times(\frac{\frac{4}{3}+2+\frac{8}{3}}{2}-\frac{8}{3})}\)

 

 

\(A=\sqrt{\frac{\frac{18}{3}}{2}\times(\frac{\frac{4}{3}+2+\frac{8}{3}}{2}-\frac{4}{3})\times(\frac{\frac{4}{3}+2+\frac{8}{3}}{2}-2)\times(\frac{\frac{4}{3}+2+\frac{8}{3}}{2}-\frac{8}{3})}\)

 

 

\(A=\sqrt{3\times(\frac{\frac{4}{3}+2+\frac{8}{3}}{2}-\frac{4}{3})\times(\frac{\frac{4}{3}+2+\frac{8}{3}}{2}-2)\times(\frac{\frac{4}{3}+2+\frac{8}{3}}{2}-\frac{8}{3})}\)

 

\(A=\sqrt{3\times(\frac{\frac{4}{3}+\frac{6}{3}+\frac{8}{3}}{2}-\frac{4}{3})\times(\frac{\frac{4}{3}+2+\frac{8}{3}}{2}-2)\times(\frac{\frac{4}{3}+2+\frac{8}{3}}{2}-\frac{8}{3})}\)

 

\(A=\sqrt{3\times(\frac{\frac{10}{3}+\frac{8}{3}}{2}-\frac{4}{3})\times(\frac{\frac{4}{3}+2+\frac{8}{3}}{2}-2)\times(\frac{\frac{4}{3}+2+\frac{8}{3}}{2}-\frac{8}{3})}\)

 

\(A=\sqrt{3\times(\frac{\frac{18}{3}}{2}-\frac{4}{3})\times(\frac{\frac{4}{3}+2+\frac{8}{3}}{2}-2)\times(\frac{\frac{4}{3}+2+\frac{8}{3}}{2}-\frac{8}{3})}\)

 

\(A=\sqrt{3\times(\frac{6}{2}-\frac{4}{3})\times(\frac{\frac{4}{3}+2+\frac{8}{3}}{2}-2)\times(\frac{\frac{4}{3}+2+\frac{8}{3}}{2}-\frac{8}{3})}\)

 

\(A=\sqrt{3\times(\frac{18}{6}-\frac{4}{3})\times(\frac{\frac{4}{3}+2+\frac{8}{3}}{2}-2)\times(\frac{\frac{4}{3}+2+\frac{8}{3}}{2}-\frac{8}{3})}\)

 

\(A=\sqrt{3\times(\frac{18}{6}-\frac{8}{6})\times(\frac{\frac{4}{3}+2+\frac{8}{3}}{2}-2)\times(\frac{\frac{4}{3}+2+\frac{8}{3}}{2}-\frac{8}{3})}\)

 

\(A=\sqrt{3\times(\frac{10}{6})\times(\frac{\frac{4}{3}+2+\frac{8}{3}}{2}-2)\times(\frac{\frac{4}{3}+2+\frac{8}{3}}{2}-\frac{8}{3})}\)

 

\(A=\sqrt{3\times(\frac{5}{3})\times(\frac{\frac{4}{3}+2+\frac{8}{3}}{2}-2)\times(\frac{\frac{4}{3}+2+\frac{8}{3}}{2}-\frac{8}{3})}\)

 

\(A=\sqrt{3\times\frac{5}{3}\times(\frac{\frac{4}{3}+2+\frac{8}{3}}{2}-2)\times(\frac{\frac{4}{3}+2+\frac{8}{3}}{2}-\frac{8}{3})}\)

 

\(A=\sqrt{\frac{3}{1}\times\frac{5}{3}\times(\frac{\frac{4}{3}+2+\frac{8}{3}}{2}-2)\times(\frac{\frac{4}{3}+2+\frac{8}{3}}{2}-\frac{8}{3})}\)

 

\(A=\sqrt{\frac{15}{3}\times(\frac{\frac{4}{3}+2+\frac{8}{3}}{2}-2)\times(\frac{\frac{4}{3}+2+\frac{8}{3}}{2}-\frac{8}{3})}\)

 

\(A=\sqrt{5\times(\frac{\frac{4}{3}+2+\frac{8}{3}}{2}-2)\times(\frac{\frac{4}{3}+2+\frac{8}{3}}{2}-\frac{8}{3})}\)

 

\(A=\sqrt{5\times(\frac{\frac{4}{3}+\frac{6}{3}+\frac{8}{3}}{2}-2)\times(\frac{\frac{4}{3}+2+\frac{8}{3}}{2}-\frac{8}{3})}\)

 

\(A=\sqrt{5\times(\frac{\frac{10}{3}+\frac{8}{3}}{2}-2)\times(\frac{\frac{4}{3}+2+\frac{8}{3}}{2}-\frac{8}{3})}\)

 

\(A=\sqrt{5\times(\frac{\frac{18}{3}}{2}-2)\times(\frac{\frac{4}{3}+2+\frac{8}{3}}{2}-\frac{8}{3})}\)

 

\(A=\sqrt{5\times(\frac{6}{2}-2)\times(\frac{\frac{4}{3}+2+\frac{8}{3}}{2}-\frac{8}{3})}\)

 

\(A=\sqrt{5\times(3-2)\times(\frac{\frac{4}{3}+2+\frac{8}{3}}{2}-\frac{8}{3})}\)

 

\(A=\sqrt{5\times(1)\times(\frac{\frac{4}{3}+2+\frac{8}{3}}{2}-\frac{8}{3})}\)

 

\(A=\sqrt{5\times1\times(\frac{\frac{4}{3}+2+\frac{8}{3}}{2}-\frac{8}{3})}\)

 

\(A=\sqrt{5\times(\frac{\frac{4}{3}+2+\frac{8}{3}}{2}-\frac{8}{3})}\)

 

\(A=\sqrt{5\times(\frac{\frac{4}{3}+\frac{6}{3}+\frac{8}{3}}{2}-\frac{8}{3})}\)

 

\(A=\sqrt{5\times(\frac{\frac{10}{3}+\frac{8}{3}}{2}-\frac{8}{3})}\)

 

\(A=\sqrt{5\times(\frac{\frac{18}{3}}{2}-\frac{8}{3})}\)

 

\(A=\sqrt{5\times(\frac{6}{2}-\frac{8}{3})}\)

 

\(A=\sqrt{5\times(3-\frac{8}{3})}\)

 

\(A=\sqrt{5\times(\frac{9}{3}-\frac{8}{3})}\)

 

\(A=\sqrt{5\times(\frac{1}{3})}\)

 

\(A=\sqrt{5\times\frac{1}{3}}\)

 

\(A=\sqrt{\frac{5}{1}\times\frac{1}{3}}\)

 

\(A=\sqrt{\frac{5}{3}}\)

.
Jun 30, 2017