2sin²∅+3sin∅=-1
find ∅
Anonymous:
so sry di, bt its not of my level.
it's ok dear :)
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Answered by
4
Hey there !
2sin²∅+3sin∅=-1
2sin²∅+2sin∅+sin∅+1=0
2sin∅(1+sin∅)+1(1+sin∅)=0
2sin∅+1(1+sin∅)=0
2sin∅+1=0
sin∅=-1/2
sin∅=sin(-30)
1+sin∅=0
sin∅=-1
∅=-30,-90,270,330
2sin²∅+3sin∅=-1
2sin²∅+2sin∅+sin∅+1=0
2sin∅(1+sin∅)+1(1+sin∅)=0
2sin∅+1(1+sin∅)=0
2sin∅+1=0
sin∅=-1/2
sin∅=sin(-30)
1+sin∅=0
sin∅=-1
∅=-30,-90,270,330
Answered by
7
Heya
Here is your answer
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2sin²∅ + 3sin∅ = -1
=> 2sin²∅ + 3sin∅ + 1 = 0
=> 2sin²∅ + 2sin∅ + sin∅ + 1 = 0
=> 2sin∅ ( sin∅ + 1 ) + 1 ( sin∅ + 1 ) = 0
=> ( 2sin∅ + 1 ) ( sin∅ + 1 ) = 0
Either
2sin∅ + 1 = 0 or sin∅ + 1 = 0
=> sin∅ = -1/2 or sin∅ = - 1
=> sin∅ = - sin30
=> sin∅ = sin ( 180 + 30 ) or sin( 360 - 30 )
= sin210 or sin330
.°. ∅ = 210, 330
Again,
sin∅ + 1 = 0
=> sin∅ = - 1
=> sin∅ = - sin90
=> sin∅ = sin( 180 + 90 ) or sin( 360 - 90 )
= sin270 or sin 270
.°. ∅ = 210 , 270, 330
thanks
====================================
Here is your answer
====================================
2sin²∅ + 3sin∅ = -1
=> 2sin²∅ + 3sin∅ + 1 = 0
=> 2sin²∅ + 2sin∅ + sin∅ + 1 = 0
=> 2sin∅ ( sin∅ + 1 ) + 1 ( sin∅ + 1 ) = 0
=> ( 2sin∅ + 1 ) ( sin∅ + 1 ) = 0
Either
2sin∅ + 1 = 0 or sin∅ + 1 = 0
=> sin∅ = -1/2 or sin∅ = - 1
=> sin∅ = - sin30
=> sin∅ = sin ( 180 + 30 ) or sin( 360 - 30 )
= sin210 or sin330
.°. ∅ = 210, 330
Again,
sin∅ + 1 = 0
=> sin∅ = - 1
=> sin∅ = - sin90
=> sin∅ = sin( 180 + 90 ) or sin( 360 - 90 )
= sin270 or sin 270
.°. ∅ = 210 , 270, 330
thanks
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