Answer: see proof below
<u>Step-by-step explanation:</u>
Use the Sum & Difference Identity: tan (A - B) = (tanA - tanB)/(1 + tanA tanB)
Use the Half-Angle Identity: tan (A/2) = (1 - cosA)/(sinA)
Use the Unit Circle to evaluate tan (π/4) = 1
Use Pythagorean Identity: cos²A + sin²A = 1
<u>Proof LHS → RHS</u>








= cos A
LHS = RHS: cos A = cos A 
Answer:
A. 2f + 10 = 28
Step-by-step explanation:
28 candy bars.
He wants 10.
28 - 10.
18 candy bars.
He gives each friend 2.
18 divided by 2.
9.
He can treat 9 friends.
Step 1: Subtract 10 from both sides.
2f+10=28
which would take away the 10 and subtract 10 from 28. (That would be Jack's bars.)
2f = 28.
Step 2: Divide by 2 on both sides.
2f = 28
which would cancel out the 2f. And Whatever is done to the left is done to the right, meaning you would divide 28 by 2 aswell. (Dividing up the candy bars among his friends).
f = 9
Answer:
standard error = 1.63
Step-by-step explanation:
To calculate the standard error we need to know the standard deviation (σ) and the sample size (n) (see the attached formula).
To obtain the standard deviation we use the given sample variance of 77.4 years:
σ²= variance
Therefore:
σ = √77.4 = 8.8
Now we can calcuate the estimated standard error:
standard error = σ /√n = 8.8/√29 = 1.63
The standard error gives us an estimation about how far the mean of the sample is from the mean of the entire population, and in this case is 1.63.
Answer:
to grow bacterial cultures