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Jack_Longstaff
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5Sin(x/2)-12Cos(x/2)=-6.5 (-360<x<360)
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GoodDay
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I personally would move the cos over to the other side then square everything, and then use an equality to get a quadratic equation in cos(0.5x). But there could be a simpler way
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brianeverit
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(Original post by Jack_Longstaff)
5Sin(x/2)-12Cos(x/2)=-6.5 (-360<x<360)
Have you come across the result
a\sin\theta-b\cos\theta=\sqrt(a^2+b^2)\sin( \theta-\alpha) \mathrm{\ where\ }\alpha=\arctan(\frac{b}{a})
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Jack_Longstaff
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no I haven't come across that, all I have come across is "addition formulae"
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davros
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(Original post by Jack_Longstaff)
no I haven't come across that, all I have come across is "addition formulae"
Are you sure you haven't come across rewriting things like AcosX + BsinX in the form Rsin(x+a) because that's probably the method that's expected here?
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