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    Hi I need help with this maths question on Trig Equations in a given interval.

    The interval is: 0_< x _< 360

    _< meaning less than or equal to

    and equation: 2Cos(x+55) -0.5 =-0.5

    Thanks in advance
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    (Original post by Vidsify)
    Hi I need help with this maths question on Trig Equations in a given interval.

    The interval is: 0_< x _< 360

    _< meaning less than or equal to

    and equation: 2Cos(x+55) -0.5 =-0.5

    Thanks in advance
    Have you written the question out correctly? The two -0.5's cancel so you're left with

    \cos (x+55) = 0

    Post all your working/ideas from here.

    Also, using <= is clearer than _<
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    this boils down to (if you re-arrange the interval taking the x+55 (i assume degrees) into acount:

    \cos(\phi)=0, 55 \leq \phi \leq 415

    where  \phi = x+55

    solve for phi in the new range, then subtract 55 deg from each solution.
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    (Original post by notnek)
    Have you written the question out correctly? The two -0.5's cancel so you're left with

    \cos (x+55) = 0

    Post all your working/ideas from here.

    Also, using <= is clearer than _<
    2Cos(x+55)-0.5=-0.5
    2Cos(x+55)=0
    Cos^-1(0)=90

    90
    360-90=270

    90-55=35
    270-55=215
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    (Original post by Vidsify)
    2Cos(x+55)-0.5=-0.5
    2Cos(x+55)=0
    Cos^-1(0)=90

    90
    360-90=270

    90-55=35
    270-55=215
    Your two solutions are correct. What help did you need? Was it the first step that I gave you in my last post?
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    (Original post by notnek)
    Your two solutions are correct. What help did you need? Was it the first step that I gave you in my last post?
    Yeah it was the first step that through me as 0/2 isn't possible.
    Thanks for your help
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    (Original post by Vidsify)
    Yeah it was the first step that through me as 0/2 isn't possible.
    Thanks for your help
    0/2 is possible it is 0
 
 
 
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