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answers:
Shelby say: Simplifying
cos(2x) + -5sinx + -3 = 0
Remove parenthesis around (2x)
cos * 2x + -5sinx + -3 = 0
Reorder the terms for easier multiplication:
2cos * x + -5sinx + -3 = 0
Multiply cos * x
2cosx + -5sinx + -3 = 0
Reorder the terms:
-3 + 2cosx + -5insx = 0
Solving
-3 + 2cosx + -5insx = 0
Solving for variable 'c'.
Move all terms containing c to the left, all other terms to the right.
Add '3' to each side of the equation.
-3 + 2cosx + 3 + -5insx = 0 + 3
Reorder the terms:
-3 + 3 + 2cosx + -5insx = 0 + 3
Combine like terms: -3 + 3 = 0
0 + 2cosx + -5insx = 0 + 3
2cosx + -5insx = 0 + 3
Combine like terms: 0 + 3 = 3
2cosx + -5insx = 3
Add '5insx' to each side of the equation.
2cosx + -5insx + 5insx = 3 + 5insx
Combine like terms: -5insx + 5insx = 0
2cosx + 0 = 3 + 5insx
2cosx = 3 + 5insx
Divide each side by '2osx'.
c = 1.5o-1s-1x-1 + 2.5ino-1
Simplifying
c = 1.5o-1s-1x-1 + 2.5ino-1
Reorder the terms:
c = 2.5ino-1 + 1.5o-1s-1x-1
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say: yeah
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Hogar say: cos2x-5sinx-3=0
cos 90 = 0, sin 90 = 1
cos 0 = 1, sin 0 = 0
cos 2x = 1-2 sin^2 x
1-2 sin^2 x -5sinx - 3 = 0
2sin^2x + 5sinx + 2 = 0
see cidyah solution
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Como say: 1 - 2 sin²x - 5 sin x - 3 = 0
2 sin²x + 5 sin x + 2 = 0
[ 2 sin x + 1 ] [ sin x + 2 ] = 0
sin x = - 1/2
x = 210⁰ , 330⁰
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Polyhymnio say: cos(2x) - 5sinx - 3 = 0
1 - 2sin²x - 5sinx - 3 = 0
2sin²x + 5sinx + 2 = 0
(2sinx + 1)(sinx + 2) = 0
sinx + 2 = 0 ==> sinx = -2. No solution since sinx is always in [-1, 1]
2sinx + 1 = 0 ==> sinx = -1/2 ==> x = 7pi/6, 11pi/6
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la console say: Do you know this identity?