Answer:

Step-by-step explanation:
we know that

Remember the identity

step 1
Find the value of 
we have that
The angle alpha lie on the III Quadrant
so
The values of sine and cosine are negative

Find the value of sine

substitute




step 2
Find the value of 
we have that
The angle beta lie on the IV Quadrant
so
The value of the cosine is positive and the value of the sine is negative

Find the value of cosine

substitute




step 3
Find cos (α + β)

we have




substitute



Answer:
A
Step-by-step explanation:
To find how long it takes for the object to hit the ground you need to set h(t)=0 after this you need to find the number that when plugged into t makes the equation equal to 0
<span>Answer:
a manufacturing process has a 70% yield, meaning that 70% of the porducts are acceptable and 30% are defective. If three of the products are randomly selected, find the probability that all of them are acceptable.
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Ans: 0.7^3 = 0.3430.</span>