Question

Question #b3c4b

Answer 1

`sin(225 ^@-30 ^@)`

`=sin(195 ^@)`
`=sin(180 ^@+15^@)`
`=-sin(15^@)`

`=-sin(60^@-45^@)`

`=-(sin60^@cos45^@-cos60^@sin45^@)`

`=-(sqrt3/2xx1/sqrt2-1/2xx1/sqrt2)`

`=-(sqrt3-1)/(2sqrt2)`