Step-by-step explanation:
½ [cos(a − b) − cos(a + b)]
Using sum and difference formulas:
½ [cos a cos b + sin a sin b − (cos a cos b − sin a sin b)]
Distribute the negative:
½ (cos a cos b + sin a sin b − cos a cos b + sin a sin b)
Combine like terms:
½ (2 sin a sin b)
Simplify:
sin a sin b
1) This probability is given by
... C(40,5)·0.12⁵·0.88³⁵ ≈ 0.18665 . . . . . where C(n, k) = n!/(k!(n-k)!)
2) This probability is given by
... 0.88⁴⁰ ≈ 0.00602
3) This is the complement of the probability that all have failed.
... 1 - 0.12⁴⁰ ≈ 1.0000
You divide 19 by 25 and then multiply by 100. The percent Jasmine got on her test is 76%.
The cost of company 1: 10x+50
The cost of company 2: 8x+60
The cost will be the same at:

The answer is 5 hours