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I understand how to use them, but can someone clearly explain to me when to use all the different formulas in Trigonometry? (For e.g: how I can tell when to use Cosine rule)
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#2
(Original post by chicchoc)
I understand how to use them, but can someone clearly explain to me when to use all the different formulas in Trigonometry? (For e.g: how I can tell when to use Cosine rule)
I understand how to use them, but can someone clearly explain to me when to use all the different formulas in Trigonometry? (For e.g: how I can tell when to use Cosine rule)
2 sides + enclosed angle to find opposite side
All 3 sides to find an angle
Sine rule:
Angle and opposite side + side to find the other opposite angle
Angle and opposite side + angle to find the other opposite side
Sine area rule:
To find area you need 2 sides + enclosed angle
To find a side you need the area + a side and the enclosed angle
In right angled triangles:
Sine:
To find angle you need opposite side + hypotenuse
To find hypotenuse you need angle + opposite side
To find opposite side you need angle + hypotenuse
Cosine:
To find angle you need adjacent side + hypotenuse
To find hypotenuse you need angle + adjacent side
To find adjacent side you need angle + hypotenuse
Tangent:
To find angle you need opposite side + adjacent side
To find adjacent side you need angle + opposite side
To find opposite side you need angle + adjacent side
Sorry if I made a mistake or my description is bad
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#3
My revision guide described the trig rules quite well; I can post a photo of the explanation.
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#4
(Original post by Loci Pi)
Cosine rule:
2 sides + enclosed angle to find opposite side
or 1 side, angle, and side opposite to the angle to find other side enclosing the angle.
Sine rule:
Angle and opposite side + side to find the other opposite angle
Angle and opposite side + angle to find the other opposite side
Sine area rule:
To find area you need 2 sides + enclosed angle
To find a side you need the area + a side and the enclosed angle
In right angled triangles:
Sine:
To find angle you need opposite side + hypotenuse
To find hypotenuse you need angle + opposite side
To find opposite side you need angle + hypotenuse
Cosine:
To find angle you need adjacent side + hypotenuse
To find hypotenuse you need angle + adjacent side
To find adjacent side you need angle + hypotenuse
Tangent:
To find angle you need opposite side + adjacent side
To find adjacent side you need angle + opposite side
To find opposite side you need angle + adjacent side
Sorry if I made a mistake or my description is bad
Cosine rule:
2 sides + enclosed angle to find opposite side
or 1 side, angle, and side opposite to the angle to find other side enclosing the angle.
Sine rule:
Angle and opposite side + side to find the other opposite angle
Angle and opposite side + angle to find the other opposite side
Sine area rule:
To find area you need 2 sides + enclosed angle
To find a side you need the area + a side and the enclosed angle
In right angled triangles:
Sine:
To find angle you need opposite side + hypotenuse
To find hypotenuse you need angle + opposite side
To find opposite side you need angle + hypotenuse
Cosine:
To find angle you need adjacent side + hypotenuse
To find hypotenuse you need angle + adjacent side
To find adjacent side you need angle + hypotenuse
Tangent:
To find angle you need opposite side + adjacent side
To find adjacent side you need angle + opposite side
To find opposite side you need angle + adjacent side
Sorry if I made a mistake or my description is bad
Cosine rule:
Three sides - use to get largest angle [oppostie largest side]
Are you sure about the seond use of cosine rule - draw a diagram as it doesn't sound correct.
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#5
(Original post by Muttley79)
Not completely correct -
Cosine rule:
Three sides - use to get largest angle [oppostie largest side]
Are you sure about the seond use of cosine rule - draw a diagram as it doesn't sound correct.
Not completely correct -
Cosine rule:
Three sides - use to get largest angle [oppostie largest side]
Are you sure about the seond use of cosine rule - draw a diagram as it doesn't sound correct.
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#7
(Original post by chicchoc)
I understand how to use them, but can someone clearly explain to me when to use all the different formulas in Trigonometry? (For e.g: how I can tell when to use Cosine rule)
I understand how to use them, but can someone clearly explain to me when to use all the different formulas in Trigonometry? (For e.g: how I can tell when to use Cosine rule)
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#14
(Original post by RuthieG101)
do you have any for c3 and c4 trig?
do you have any for c3 and c4 trig?
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