I dont know how to do this, please show work
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sin(2theta)+3cos(theta)=0
2007-10-28 04:23:59 · 4 answers · asked by ted 1 in Science & Mathematics ➔ Mathematics
sin 2θ + 3 cos θ = 0
2 sin θ cos θ + cos θ = 0
cos θ (2sin θ + 1) = 0
cos θ = 0 , sin θ = - 1/2
θ = 90° , 270° , 210° , 330°
OR
θ = π/2 , 3π/2 , 7π/6 , 10π/6
2007-10-28 09:01:39 · answer #1 · answered by Como 7 · 1⤊ 0⤋
Let x be theta.
2sinxcosx+3cosx = 0
cosx(2sinx+3) = 0
cosx = 0, the only solutioin since 2sinx+3 ≠ 0.
x = 0 + 2npi, where n can be any integer.
2007-10-28 04:30:06 · answer #2 · answered by sahsjing 7 · 1⤊ 1⤋
sin(2x) = 2sin(x)cos(x)... ok?
Now, add, factor (use the distributive proper of ad dition overmultiplication a(b+c)=ab+ac), set each factor = 0 and solve.
I'm not sure why the gurus didn't respond at least this far. Perhaps they didn't get it? ;-)
2007-10-28 04:37:06 · answer #3 · answered by gugliamo00 7 · 0⤊ 1⤋
OK that is like impossible to DO!!! tell Ur teacher i said go easy on the math OMG!!! my math is way easyer like this 350 divided by 9050 or like 3.5x-7.4x+1.5=3.6
2007-10-28 04:32:25 · answer #4 · answered by ? 2 · 0⤊ 1⤋