Which inverse trigonometric function will determine the measurement of b? cos-1(0.6) sin-1(0.8) tan-1(0.75) cot (0.75)

How do you use the elimination method for this question? explain, because i really want to understand!

What values of x satisfy the inequality x^2-9x< 0? how is your answer shown on the graph?

Given: lines a and b are parallel and line c is a transversal. prove: 2 is supplementary to 8 what is the missing reason in the proof? statement reason 1. a || b, is a transv 1. given 2. ∠6 ≅ ∠2 2. ? 3. m∠6 = m∠2 3. def. of congruent 4. ∠6 is supp. to ∠8 4. def. of linear pair 5. ∠2 is supp. to ∠8 5. congruent supplements theorem corresponding angles theorem alternate interior angles theorem vertical angles theorem alternate exterior angles theorem