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3 years ago

18=30-r30 solve for r

Mathematics

2 answers:

alisha [4.7K]3 years ago

6 0

Answer:

r=2/5

Step-by-step explanation:

trasher [3.6K]3 years ago

3 0

Answer:

r =

Step-by-step explanation:

r=30√12,−30√12

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Use (a) the midpoint rule and (b) simpson's rule to approximate the below integral. ∫ x^2sin(x) dx with n = 8.

MaRussiya [10]

Answer:

midpoint rule = 5.93295663

simpson's rule = 5.869246855

Step-by-step explanation:

a) midpoint rule

$\int\limits^b_a {(x)} \, dx$ ≈ Δ x (f(x₀+x₁)/2 + f(x₁+x₂)/2 + f(x₂+x₃)/2 +...+ f(x $_{n}$ _₂+x $_{n}$ _₁)/2 +f(x $_{n}$ _₁+x $_{n}$ )/2)

Δx = (b − a) / n

We have that a = 0, b = π, n = 8

Therefore

Δx = (π − 0) / 8 = π/8

Divide the interval [0,π] into n=8 sub-intervals of length Δx = π/8 with the following endpoints:

a=0, π/8, π/4, 3π/8, π/2, 5π/8, 3π/4, 7π/8, π = b

Now, we just evaluate the function at these endpoints:

$f(\frac{x_{0}+x_{1} }{2} ) = f(\frac{0+\frac{\pi}{8} }{2} ) = f(\frac{\pi }{16})=\frac{\pi^{2}sin(\frac{\pi }{16}) }{256} =$ 0.00752134

$f(\frac{x_{1}+x_{2} }{2} ) = f(\frac{\frac{\pi }{8} +\frac{\pi}{4} }{2} ) = f(\frac{3\pi }{16})=\frac{9\pi ^{2} sin(\frac{3\pi }{16}) }{256}$ = 0.19277080

$f(\frac{x_{2}+x_{3} }{2} ) = f(\frac{\frac{\pi }{4} +\frac{3\pi}{8} }{2} ) = f(\frac{5\pi }{16})=\frac{25\pi ^{2} sin(\frac{5\pi }{16}) }{256}$ = 0.80139415

$f(\frac{x_{3}+x_{4} }{2} ) = f(\frac{\frac{3\pi }{8} +\frac{\pi}{2} }{2} ) = f(\frac{7\pi }{16})=\frac{49\pi ^{2} sin(\frac{7\pi }{16}) }{256}$ = 1.85280536

$f(\frac{x_{4}+x_{5} }{2} ) = f(\frac{\frac{\pi }{2} +\frac{5\pi}{8} }{2} ) = f(\frac{9\pi }{16})=\frac{81\pi ^{2} sin(\frac{7\pi }{16}) }{256}$ = 3.062800704

$f(\frac{x_{5}+x_{6} }{2} ) = f(\frac{\frac{5\pi }{8} +\frac{3\pi}{4} }{2} ) = f(\frac{11\pi }{16})=\frac{121\pi ^{2} sin(\frac{5\pi }{16}) }{256}$ = 3.878747709

$f(\frac{x_{6}+x_{7} }{2} ) = f(\frac{\frac{3\pi }{4} +\frac{7\pi}{8} }{2} ) = f(\frac{13\pi }{16})=\frac{169\pi ^{2} sin(\frac{3\pi }{16}) }{256}$ = 3.61980731

$f(\frac{x_{7}+x_{8} }{2} ) = f(\frac{\frac{7\pi }{8} +\pi }{2} ) = f(\frac{15\pi }{16})=\frac{225\pi ^{2} sin(\frac{\pi }{16}) }{256}$ = 1.69230261

Finally, just sum up the above values and multiply by Δx = π/8:

π/8 (0.00752134 +0.19277080+ 0.80139415 + 1.85280536 + 3.062800704 + 3.878747709 + 3.61980731 + 1.69230261) = 5.93295663

b) simpson's rule

$\int\limits^b_a {(x)} \, dx$ ≈ (Δx)/3 (f(x₀) + 4f(x₁) + 2f(x₂) + 4f(x₃) + 2f(x₄) + ... + 2f( $x_{n-2}$ ) + 4f( $x_{n-1}$ ) + f( $x_{n}$ ))

where Δx = (b−a) / n

We have that a = 0, b = π, n = 8

Therefore

Δx = (π−0) / 8 = π/8

Divide the interval [0,π] into n = 8 sub-intervals of length Δx = π/8, with the following endpoints:

a = 0, π/8, π/4, 3π/8, π/2, 5π/8, 3π/4, 7π/8 ,π = b

Now, we just evaluate the function at these endpoints:

f(x₀) = f(a) = f(0) = 0 = 0

$4f(x_{1} ) = 4f(\frac{\pi }{8} )=\frac{\pi^{2}\sqrt{\frac{1}{2}-\frac{\sqrt{2} }{4} } }{16}$ = 0.23605838

$2f(x_{2} ) = 2f(\frac{\pi }{4} )=\frac{\sqrt{2\pi^{2} } }{16}$ = 0.87235802

$4f(x_{3} ) = 4f(\frac{3\pi }{8} )=\frac{9\pi^{2}\sqrt{\frac{\sqrt{2} }{4}-\frac{{1} }{2} } }{16}$ = 5.12905809

$2f(x_{4} ) = 2f(\frac{\pi }{2} )=\frac{\pi ^{2} }{2}$ = 4.93480220

$4f(x_{5} ) = 4f(\frac{5\pi }{8} )=\frac{25\pi^{2}\sqrt{\frac{\sqrt{2} }{4}-\frac{{1} }{2} } }{16}$ = 14.24738359

$2f(x_{6} ) = 2f(\frac{3\pi }{4} )=\frac{9\sqrt{2\pi^{2} } }{16}$ = 7.85122222

$4f(x_{7} ) = 4f(\frac{7\pi }{8} )=\frac{49\pi^{2}\sqrt{\frac{1}{2}-\frac{\sqrt{2} }{4} } }{16}$ = 11.56686065

f(x₈) = f(b) = f(π) = 0 = 0

Finally, just sum up the above values and multiply by Δx/3 = π/24:

π/24 (0 + 0.23605838 + 0.87235802 + 5.12905809 + 4.93480220 + 14.24738359 + 7.85122222 + 11.56686065 = 5.869246855

7 0

3 years ago

which of the binomials below is a factor of this trinomial? x^2 + 5x - 36 A. x - 5 B. x - 9 C. x + 9 D. x^2 + 5

bazaltina [42]

<h3>Answer: C. x+9</h3>

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

Explanation:

Think of two numbers that multiply to -36 and also add to 5. Put another way: think of two factors of -36 that add to 5.

Those two numbers are 9 and -4 since

9 times -4 = -36

9 plus -4 = 5

So we have x^2 + 5x - 36 factor into (x+9)(x-4)

x+9 is one factor

x-4 is the other factor

-------

Alternatively, you can use a graphing tool to locate the x intercepts, and that will in turn lead to the factorization. Or you could use the quadratic formula to get the job done. Completing the square is yet another tool to use. So there are multiple approaches.

7 0

4 years ago

PLEASE ANSWER IT QUICKLY IT'S VERY IMPORTANT!!!!!!!!!!

Marizza181 [45]

Answer:

Number 2 is A and number 3 Is A.

Step-by-step explanation:

divide

4 0

3 years ago

Read 2 more answers