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Trigonometry, SMB-004

Without the use of a calculator, express the following as a fraction

  1. `sin 30^{@}`   (1 mark)

  2. `sin 60^{@}`   (2 marks)

Show Answers Only
  1. `sin 30^{@} = 1/2`
  2. `sin 60^{@} = sqrt3/2`
Show Worked Solution

i.    `sin 30^{@} = text{opp}/text{hyp} = 1/2`

ii.   `text{Let}\ \ x =\ text{unknown side}`

`text{By Pythagoras:}`

`2^2` `=x^2 + 1^2`  
`x^2` `=4-1`  
`x` `=sqrt3\ \ (x>0)`  

 
`sin 60^{@} = text{opp}/text{hyp} = sqrt3/2`