Question

How do you find the exact value of `cos70sin48-cos48sin70` using the sum and difference, double angle or half angle formulas?

Answer 1

`sin(-22) = -sin22`

Explanation:

From the equation, you can tell that it is `sin(a-b)`

`sin(a-b) = cosbsina-cosasinb`

When comparing with the equation, we can say that `a=48, b=70`

`sin(a-b) = sin (48-70)` = `sin(-22) = -sin(22)`