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3 years ago

Very confused especially on number three.

Mathematics

1 answer:

kogti [31]3 years ago

5 0

Answer:

yes it was so confused for me too

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Rewrite in Polar Form.... x^(2)+y^(2)-6y-8=0

skad [1K]

$\bf x^2+y^2-6y-8=0\qquad 
\begin{cases}
x^2+y^2=r^2\\\\
y=rsin(\theta)
\end{cases}\implies r^2-6rsin(\theta)=8
\\\\\\
\textit{now, we do some grouping}\implies [r^2-6rsin(\theta)]=8
\\\\\\\
[r^2-6rsin(\theta)+\boxed{?}^2]=8\impliedby 
\begin{array}{llll}
\textit{so we need a value there to make}\\
\textit{a perfect square trinomial}
\end{array}$

$\bf 6rsin(\theta)\iff 2\cdot r\cdot \boxed{3\cdot sin(\theta)}\impliedby \textit{so there}
\\\\\\
\textit{now, bear in mind we're just borrowing from zero, 0}
\\\\
\textit{so if we add, \underline{whatever}, we also have to subtract \underline{whatever}}$

$\bf [r^2-6rsin(\theta)\underline{+[3sin(\theta)]^2}]\quad \underline{-[3sin(\theta)]^2}=8\\\\
\left. \qquad \right.\uparrow \\
\textit{so-called "completing the square"}
\\\\\\\
[r-3sin(\theta)]^2=8+[3sin(\theta)]^2\implies [r-3sin(\theta)]^2=8+9sin^2(\theta)
\\\\\\
r-3sin(\theta)=\sqrt{8+9sin^2(\theta)}\implies r=\sqrt{8+9sin^2(\theta)}+3sin(\theta)$

3 0

3 years ago

If there are initially 1800 bacteria in a culture, and the number of bacteria double each hour, the number of bacteria after t h

Nataly_w [17]

Answer: 1.58 hours

Step-by-step explanation:

$5400=1800(2)^t\\\\3=2^t\\\\ln\ 3=ln\ 2^t\\\\ln\ 3=t\cdot ln\ 2\\\\\dfrac{ln\ 3}{ln\ 2}=t\\\\1.58=t$

5 0

3 years ago

Solve using the guess-and-check strategy.

Nadya [2.5K]

The answer is 12. Matthew would be 12 & Elizabeth would be 7. 12+7=19. So C is your answer.

7 0

3 years ago

Read 2 more answers

DESCRIBE

Vanyuwa [196]

Answer:

It represents the height between Hank and Tim on the Mountain/ Or how much higher is Tim than Hank.

Step-by-step explanation:

Since Tim is higher than Hank on the Mountain, and he is on 33 above, and Hank is 126 feet below, this represents the height between Hank and Tim on the Mountain.

8 0

2 years ago

Read 2 more answers

PLEASE SHOW FULL SOLUTIONS !!!!! WILL MARK BRAINLIEST FOR THE BEST ANSWER. THANK YOU AND GOD BLESS

yanalaym [24]

Answer:

System is given below

Step-by-step explanation:

Let (applicable to all three lines below)
Hard candy = x kg with price $1.60/kg
Gummy worms = y kg with price $2.20/kg
Total weight = 50 kg with mixed price $1.75/kg

Required equations:

x + y = 50 total weight
1.60x + 2.20y = 50*1.75 total price

=========================================

Note. It says don't solve but the solution below for those who is interested to know the answer.

Simplify the second equation and solve by substitution x = 50 - y:

1.6(50 - y) + 2.2y = 87.5
80 - 1.6y +2.2y = 87.5
0.6y = 7.5
y = 7.5/0.6
y = 12.5

Find the value of x:

x = 50 - 12.5 = 37.5

Hard candy = 37.5 kg and gummy worms = 12.5 kg

7 0

2 years ago