Let's simplify the expression step by step:

Step 1: Calculate sin 77 degrees, sin 257 degrees, and cos 450 degrees.

sin 77 degrees ≈ 0.9744sin 257 degrees ≈ -0.9744cos 450 degrees = cos(360 + 90) = cos 90 degrees = 0

Step 2: Substitute the values into the expression.
(3 0.9744 - 3 (-0.9744) - 0) / cos 13 degrees

Step 3: Simplify further.
(2.9232 + 2.9232) / cos 13 degrees
5.8464 / cos 13 degrees

Therefore, the simplified expression is 5.8464 / cos 13 degrees.