An electrician uses 46 3/4 feet of push-back wire from a 200-foot roll. How many feet of wire are left on the roll?
1 answer:
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Answer:
see explanation
Step-by-step explanation:
(4)
consider the left side
factor the numerator
cosx - cos³x = cosx(1 - cos²x)
cancel sinx on numerator/denominator
= cosxsinx =right side ⇒ verified
(5)
Consider the left side
expand the factors
(1 + cotΘ)² + (1 - cotΘ)²
= 1 + 2cotΘ + cot²Θ + 1 - 2cotΘ + cot²Θ
= 2 + 2cot²Θ
= 2(1 + cot²Θ) ← 1 + cot²Θ = cosec²Θ
= 2cosec²Θ = right side ⇒ verified
(6)
Consider the left side
the denominator simplifies to
cosxtanx = cosx × = sinx
= sinx( +
)
= +
= tanx + 1 = right side ⇒ verified
Answer:
0.45% probability that they are both queens.
Step-by-step explanation:
A probability is the number of desired outcomes divided by the number of total outcomes
The combinations formula is important in this problem:
is the number of different combinations of x objects from a set of n elements, given by the following formula.
Desired outcomes
You want 2 queens. Four cards are queens. I am going to call then A,B,C,D. A and B is the same outcome as B and A. That is, the order is not important, so this is why we use the combinations formula.
The number of desired outcomes is a combinations of 2 cards from a set of 4(queens). So
Total outcomes
Combinations of 2 from a set of 52(number of playing cards). So
What is the probability that they are both queens?
0.45% probability that they are both queens.