Answer: 84 mm is MAYBE the answer.
Answer: see proof below
<u>Step-by-step explanation:</u>
Given: A + B + C = π and cos A = cos B · cos C
scratchwork:
A + B + C = π
A = π - (B + C)
cos A = cos [π - (B + C)] Apply cos
= - cos (B + C) Simplify
= -(cos B · cos C - sin B · sin C) Sum Identity
= sin B · sin C - cos B · cos C Simplify
cos B · cos C = sin B · sin C - cos B · cos C Substitution
2cos B · cos C = sin B · sin C Addition
Division
2 = tan B · tan C

<u>Proof LHS → RHS</u>
Given: A + B + C = π
Subtraction: A = π - (B + C)
Apply tan: tan A = tan(π - (B + C))
Simplify: = - tan (B + C)

Substitution: = -(tan B + tan C)/(1 - 2)
Simplify: = -(tan B + tan C)/-1
= tan B + tan C
LHS = RHS: tan B + tan C = tan B + tan C 
Exact Form : -53/12
Decimal Form : -4.416
Mixed numbers : -4 5/12
Answer:
-24
Step-by-step explanation:
If you are struggling with this here's a tip!
-18+-6 is what you are trying to solve
The 6 is negative, so get rid of the plus sign -18-6
2 negative numbers are just added like positive numbers
So add 18 and 6, you should get 24
Don't forget about the negative!
-24
Answer:
She needs to sample 189 trees.
Step-by-step explanation:
We have that to find our
level, that is the subtraction of 1 by the confidence interval divided by 2. So:

Now, we have to find z in the Ztable as such z has a pvalue of
.
That is z with a pvalue of
, so Z = 1.96.
Now, find the margin of error M as such

In which
is the standard deviation of the population and n is the size of the sample.
The standard deviation of the population is 70 peaches per tree.
This means that 
How many trees does she need to sample to obtain an average accurate to within 10 peaches per tree?
She needs to sample n trees.
n is found when M = 10. So



Dividing both sides by 10:



Rounding up:
She needs to sample 189 trees.