Pre calculus honors verify the identity

Question

Sin(a-b)

———— = tana-tanb

cosacosb

these lines ————- are basically the divided mark line thing

Answer 1

Verify:

sin(a-b)/(cos(a)cos(b)) = tan(a)-tan(b)

Using sine difference formula

(sin(a)cos(b) - sin(b)cos(a))/(cos(a)cos(b)) = sin(a)cos(b)/(cos(a)cos(b)) - sin(b)cos(a)/(cos(a)cos(b))

Do division cancellation and use sin/cos = tan:

sin(a)/cos(a) - sin(b)/cos(b) = tan(a) - tan(b)