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3 years ago

R2+2r-33=0 solve by completing the square

1 answer:

8 0

R^2+2r-33=0 move constant to other side by adding 33 to both sides

r^2+2r=33 halve the linear coefficient, square it and add to both sides, in this case it is just one

r^2+2r+1=34 now the left side is a perfect square...

(r+1)^2=34 take the square root of both sides...

r+1=34^(1/2) subtract 1 from both sides

r=-1+34^(1/2) and -1-34^(1/2)

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Suppose that the dollar cost of producing x radios is c(x) = 400 + 20x - 0.2x 2. Find the marginal cost when 30 radios are produ

My name is Ann [436]

C(x) = 400 + 20x - 0.2x²

c(30) = 400 + 20(30) - 0.2(30)²

= 400 + 600 - 0.2(900)
= 1000 - 180
= 820

It costs $820 when 30 radios are produced.

Marginal cost is how much it would cost to make one MORE of the same product so now we find how much it costs to produce 31 radios and compare the two.

c(31) = 400 + 20(31) - 0.2(31)²

= 400 + 620 - 0.2(961)
= 1020 - 192.2
= 827.8 or ≈828.

Now we find the difference which means we subtract the two.

828 - 820 = 8.

Your marginal cost is $8.

To compare we can also do 29 radios.

c(29) = 400 + 20(29) - 0.2(29)² = 811.8 or ≈812

820 - 812 = 8.

7 0

3 years ago

If a coin is tossed three times, find probability of getting

Assoli18 [71]

${\large{\textsf{\textbf{\underline{\underline{Given :}}}}}}$

‣ A coin is tossed three times.

${\large{\textsf{\textbf{\underline{\underline{To \: Find :}}}}}}$

‣ The probability of getting,

1) Exactly 3 tails

2) At most 2 heads

3) At least 2 tails

4) Exactly 2 heads

5) Exactly 3 heads

${\large{\textsf{\textbf{\underline{\underline{Using \: Formula :}}}}}}$

$\star \: \tt P(E)= {\underline{\boxed{\sf{\red{ \dfrac{ Favourable \: outcomes }{Total \: outcomes} }}}}}$

${\large{\textsf{\textbf{\underline{\underline{Solution :}}}}}}$

★ When three coins are tossed,

then the sample space = {HHH, HHT, THH, TTH, HTH, HTT, THT, TTT}

[here H denotes head and T denotes tail]

⇒Total number of outcomes $\tt [ \: n(s) \: ]$ = 8

1) Exactly 3 tails 

Here

• Favourable outcomes = {HHH} = 1

• Total outcomes = 8

$\therefore \sf Probability_{(exactly \: 3 \: tails)} = \red{ \dfrac{1}{8}}$

2) At most 2 heads

[It means there can be two or one or no heads]

Here

• Favourable outcomes = {HHT, THH, HTH, TTH, HTT, THT, TTT} = 7

• Total outcomes = 8

$\therefore \sf Probability_{(at \: most \: 2 \: heads)} = \green{ \dfrac{7}{8}}$

3) At least 2 tails 

[It means there can be two or more tails]

Here

• Favourable outcomes = {TTH, TTT, HTT, THT} = 4

• Total outcomes = 8

$\longrightarrow \sf Probability_{(at \: least \: 2 \: tails)} = \dfrac{4}{8}$

$\therefore \sf Probability_{(at \: least \: 2 \: tails)} = \orange{\dfrac{1}{2}}$

4) Exactly 2 heads 

Here

• Favourable outcomes = {HTH, THH, HHT } = 3

• Total outcomes = 8

$\therefore \sf Probability_{(exactly \: 2 \: heads)} = \pink{ \dfrac{3}{8}}$

5) Exactly 3 heads

Here

• Favourable outcomes = {HHH} = 1

• Total outcomes = 8

$\therefore \sf Probability_{(exactly \: 3 \: heads)} = \purple{ \dfrac{1}{8}}$

$\rule{280pt}{2pt}$

8 0

1 year ago

Roni's parents are planning a vacation. They found a cabin to rent for $75 a day with no deposit. They also found a hotel that w

densk [106]

Answer:

The answer is C

Step-by-step explanation:

5 0

3 years ago

If your dinner bill was $80 and you left a 15% tip. How much money did you leave as a tip? What is your total bill cost?

nadya68 [22]

Answer: 92 dollars because 15% divided into 80 is 12 and add 80 to 12 and its 92

6 0

2 years ago

Write a cubic function whose graph passes through the points.

SpyIntel [72]

Answer:

(0,9) (-1,0), (2,0), (3,0),

Step-by-step explanation:

add me on discord LD BrxzyYT#8144 :)

7 0

2 years ago