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Solve each equation 12sin^2-13sinx+3=0​

1 Answer

5 votes

Answer:

Explanation:

(I assume it's
12sin^2 x -13 sinx +3 = 0)

Start by setting
sinx = y (or whichever letter you prefer). Your equation becomes
12y^2 -13y +3 = 0 . Solving for y you get
y = \frac {-(-13) \pm √(13^2 - 4*3*12) } {2*12} =\frac{ 13 \pm √(13^2-12^2)} {24} = \frac {13 \pm5 }{24}\\ y = \frac {18} {24} = \frac 34; y= \frac 8 {24} = 1/3

But we're not done yet. Since we said
sinx = y, you need to solve both
sinx = \frac 3 4 and
sinx = \frac 1 3, whose solutions are the inverse sine of said values, plus any number of complete rotations.

User Ylzhang
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