Question

How do you find the exact value of `sin35cos60-cos35sin60` using the sum and difference, double angle or half angle formulas?

Answer 1

Answer: `sin(-25^@)=sin(335)`

Explanation:

Consider the difference identity for sine:
`sin(a+-b)=sinacosb+-cosasinb`

Using this formula, we can see that `a=35` and `b=60`
Therefore:
`sin35cos60-cos35sin60`
`=sin(35-60)`
`=sin(-25)`
`=sin(335)` which is not a special unit circle trig value so we cannot simplify any further