Whats Cosine240XSin150 + Sin300XCos300?

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Whats Cosine240XSin150 + Sin300XCos300?

2007-10-11 15:11:19 · 2 answers · asked by anthonyw w 2 in Education & Reference ➔ Homework Help

2 answers

cos(240) * sin(150) + sin(300)cos(300)
= -cos(60) * sin(30) - sin(60)cos(60)
= -(1/2)*(1/2) - (sqrt(3)/2)(1/2)
= - (sqrt(3) + 1) / 4.

2007-10-15 02:56:53 · answer #1 · answered by Anonymous · 0⤊ 0⤋

I cheated and used Excel. I don't know if these will be of any value at because of excel's rounding:

COS(240) = .3258 or approx 1/3
SIN(150) = -.7149 or approx -5/7
SIN(300) = 1
COS(300) = 0

Final answer: -.2329 or approx -1/4

2007-10-12 04:31:36 · answer #2 · answered by nytebreid 7 · 0⤊ 0⤋