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Oliga [24]
3 years ago
5

(9x+7)(9x-7) what's the answer

Mathematics
2 answers:
MrRa [10]3 years ago
8 0
They cancel each other out because one is + and the other is -.
EastWind [94]3 years ago
4 0

81x^2 - 49. The middle terms cancel out because of the opposing signs, but the answer is 81x^2 - 49

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For f(x)=4sin(x2) between x=0 and x=3, find the coordinates of all intercepts, critical points, and inflection points to two dec
telo118 [61]

Answer:

Intercepts:

x = 0, y = 0

x = 1.77, y = 0

x = 2.51, y = 0

Critical points:

x = 1.25, y = 4

x = 2.17 , y = -4

x = 2.8, y = 4

Inflection points:

x = 0.81, y = 2.44

x = 1.81, y = -0.54

x = 2.52, y = 0.27

Step-by-step explanation:

We can find the intercept by setting f(x) = 0

4sin(x^2) = 0

sin(x^2) = 0

x^2 = n\pi where n = 0, 1, 2,3, 4, 5,...

x = \sqrt(n\pi)

Since we are restricting x between 0 and 3 we can stop at n = 2

So the function f(x) intercepts at y = 0 and x:

x = 0

x = 1.77

x = 2.51

The critical points occur at the first derivative = 0

f^{'}(x) = 4cos(x^2)2x = 8xcos(x^2) = 0

xcos(x^2) = 0

x = 0 or

cos(x^2) = 0

x^2 = \frac{\pi}{2} + n\pi where n = 0, 1, 2, 3

x = \sqrt{\pi(n+1/2)}

Since we are restricting x between 0 and 3 we can stop at n =  2

So our critical points are at

x = 1.25, y = f(1.25) = 4sin(1.25^2) = 4

x = 2.17 , y = f(2.17) = 4sin(2.17^2) = -4

x = 2.8, y = f(2.8) = 4sin(2.8^2) = 4

For the inflection point, we can take the 2nd derivative and set it to 0

f^[''}(x) = 8(cos(x^2) - xsin(x^2)2x) = 8cos(x^2) - 16x^2sin(x^2) = 0

cos(x^2) = 2x^2sin(x^2)

tan(x^2) = \frac{1}{2x^2}

We can solve this numerically to get the inflection points are at

x = 0.81, y = f(0.81) = 4sin(0.81^2) = 2.44

x = 1.81, y = f(1.81) = 4sin(1.81^2) = -0.54

x = 2.52, y = f(2.52) = 4sin(2.52^2) = 0.27

3 0
3 years ago
Alex needs to catch a train. The train arrives randomly some time between $1:00$ and $2:00$, waits for $10$ minutes, and then le
creativ13 [48]

The probability that the train will be there when Alex arrives is 5/18

If Alex arrives at any time after 1.20pm the chances that train will  be there is 1/3.

However  if alex arrives at 1.00pm exactly there is no chance the train will be arrive there.

The probability that the train will be there increase linearly to 1/3 as alex's arrival time moves from 1.00pm to 1.20pm.

By arranging the probabilities over the first 20 minutes to get a 1/6 chance the train will be there if alex arrives between 1.00pm to 1.20pm

we get the final answer by

=1/3( 1/6 + 1/3 + 1/3)

=5/18

So, the probability that the train will be there when Alex arrives is 5/18

Learn more about PROBABILITY here

brainly.com/question/24756209

#SPJ4

3 0
2 years ago
The circle passes through the point (-1,-6). What is its radius?
love history [14]

Answer:

the radius is something in math

3 0
3 years ago
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What are two possible transformations that together could have been used to create the red figure from the blue figure?
attashe74 [19]
Id say <em>2 and 3 . </em><em /> It has to reflect off of the Y axis to look like the red figure. Other than that I can't help.
3 0
3 years ago
Read 2 more answers
1. Sally said that when you add or subtract positive or negative decimals, you can change the order of the decimals and still ge
Oduvanchick [21]

can you type the decimals in the comments
7 0
3 years ago
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