* Show your work : 1. Determine the reference angle for ". Draw the angle on the unit circle.* Show your work i 2. Verify the identity (1 + tanu)(1 - sinu) = 1. Write the rule at each step.* Show your work i 3. Use the figure to find the exact value of the trigonometric function. Find sin (20) 17 15 8* Show your work i 4. Use a half-angle formula to find the exact value of the expression. cos* Show your work : 5. Solve the equations: a) cosx = - Find all solutions. Show the solutions on each) the unit circle for both a ) and b ) . b) csc20 - csco - 2 = 0 on the interval [0, 2nt).6. Use the given information to find the exact value of the expression. tan a = >, a a lies in quadrant III, and coss = - B lies in quadrant II Find: cos (a + B)