The function p(x) = -2(x - 9)2 + 100 is used to determine the profit on T-shirts sold for x dollars. What would the
1 answer:
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Answer:
Step-by-step explanation:
Multiply out in order to find out which expression it is equivalent to.
1) Since the whole quantity is squared, write it out as .
2) Multiply binomials by using the FOIL method. Multiply the terms that are listed first in each binomial, then the ones that are listed outermost when looking at both binomials, then innermost, and finally the last terms listed in each binomial. Simplify and combine like terms.
3) , so
must be
. Thus,
is equivalent to -1. Knowing this, simplify and combine like terms.
Thus, it is equivalent to .
Answer:
11.51
Step-by-step explanation:
In general, a calculator is required to evaluate the irrational sum ...
π + √70
<h3>Calculator result</h3>The result from a readily-available online calculator is shown in the attachment.
π + √70 ≈ 11.51
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<em>Additional comment</em>
You have probably memorized pi to several digits: 3.1416. To obtain the required estimate means you need to approximate √70 to about the same level of precision.
For a number n = a² +b, the square root can be approximated by the continued fraction ...
√n ≈ a +b/(2a +b/(2a +...))
Effectively, the root (r) can be iterated from the recursive formula ...
r' = a +b/(a +r)
For √70, we have 70 = 8² +6 ⇒ a=8, b=6
If the initial approximation of the root is r0≈a=8, then a couple of iterations gives ...
r1 = 8 + 6/(8 +r0) = 8 + 6/(8 +8) = 8 3/8
r2 = 8 + 6/(8 +r1) = 8 +6/(8 +8 3/8) = 8 48/131
This has sufficient accuracy for the purpose. The decimal equivalent of the sum then becomes ...
3.1416 +8.3664 = 11.5080 ≈ 11.51
