Use a sum or difference formula to find an exact value of  $\sin\left(\frac{7\pi}{12}\right)$  

If  cos θ = 4/5  and  $\frac{3\pi}{2}<\theta<2\pi$ 

Find sin 2θ

Find the exact value of  $\sin2x$    if  $\sin x=\frac{12}{13}$   and x is in the first quadrant. 

If  $\sin A=\frac{3}{5},\sin B=\frac{2}{3},$   $and\ \angle A\ and\ \angle B$  are in the first quadrant, what is the value of  $\cos\left(A-B\right)?$  

If $\sin A=\frac{4}{5},\tan B=\frac{5}{12},$  and A and B are first quadrant angles, what is the value of  $\sin\left(A+B\right)$  ?

If $\sin\theta=\frac{\sqrt{5}}{3}$   and  $\frac{\pi}{2}<\theta<\pi$  ,  then  $\cos2\theta$  equals

Use sum or difference angles identity to find the exact value for       $\sin\ \left(\frac{-\pi}{12}\right)$  

Find the exact value of  $\sin2\theta$  if   $\sin\theta=\frac{12}{13}$   and  $\theta$   is in the first quadrant. 

If cos θ = 4/5  and  $\frac{3\pi}{2}<\theta<2\pi$  ,  find sin 2θ

If A and B are first quadrant angles with sinA=15/17 and cosB=4/5, find cos(A - B).