2.4 Sum and Difference Formulas - Problem Check-in

cos (A - B)= (leave no spaces in answer)

(a)  

Fill in the rest after the plus sign (no spaces):

sin(A+B)=sinAcosB +

(a)  

If  $\sin\alpha=\frac{5}{13}$  and  $\cos\beta=\frac{4}{5}$  (both in QI), then find  $\sin\left(\alpha-\beta\right)$  

sin (A - B) = (leave no spaces when typing answer)

(a)  

Find the exact value of the expression.
$$\sin\left(\frac{5\pi}{12}\right)\cos\left(\frac{\pi}{4}\right)-\cos\left(\frac{5\pi}{12}\right)\sin\left(\frac{\pi}{4}\right)$$  

cos (A + B)= (leave no spaces in answer)

(a)  

Use a sum or difference formula to find an exact value of sin 105º