SOLUTION: How do I solve the following question: 8 sin cube x - 18 sin square x + 13 sinx - 3 = 0, xE[-pi/2, pi)?

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Question 396007: How do I solve the following question: 8 sin cube x - 18 sin square x + 13 sinx - 3 = 0, xE[-pi/2, pi)?
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
Sub y for sin(x)
8y%5E3+-+18y%5E2+%2B+13y+-+3+=+0
You can see that 8+13 = -(-18-3) so f(-1) = 0 and y=1 is a zero.
Divide by (y-1) and solve the quadratic.
Sub sin(x) for y.