I got stuck on this question. Use long division to solve
1 answer:
Answer:
5x² +19x +76 +310/(x-4)
Step-by-step explanation:
The process is straightforward. Find the quotient term, multiply it by the divisor and subtract from the dividend to get the new dividend. Repeat until the dividend is a constant (lower-degree than the divisor).
The tricky part with this one is realizing that there is no x-term in the original dividend, so that term needs to be added with a 0 coefficient. The rather large remainder is also unexpected, but that's the way this problem unfolds.
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Unlike numerical long division, polynomial long division is simplified by the fact that the quotient term is the ratio of the highest-degree terms of the dividend and divisor. Here, the first quotient term is (5x^3)/(x) = 5x^2.
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The solutions appear to be {π/2, 2π/3, 4π/3}.
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Replacing sin(2x) with 2sin(x)cos(x), you have
2sin(x)cos(x) +sin(x) -2cos(x) -1 = 0
sin(x)(2cos(x) +1) -(2cos(x) +1) = 0 . . . . factor by grouping
(sin(x) -1)(2cos(x) +1) = 0
This has solutions
sin(x) = 1
x = π/2
and
2cos(x) = -1
cos(x) = -1/2
x = {2π/3, 4π/3}
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Replacing sin(2x) with 2sin(x)cos(x), you have
2sin(x)cos(x) +sin(x) -2cos(x) -1 = 0
sin(x)(2cos(x) +1) -(2cos(x) +1) = 0 . . . . factor by grouping
(sin(x) -1)(2cos(x) +1) = 0
This has solutions
sin(x) = 1
x = π/2
and
2cos(x) = -1
cos(x) = -1/2
x = {2π/3, 4π/3}