Answer:
(1-cos2A) /(1+cos2A) =tan²A
Proof:
We know that,
cos(A+B) =cosA.cosB-sinA.sinB
=>cos2A=cos(A+A)
=>cos2A=cosA.cosA - sinA.sinA
=>cos2A=cos²A-sin²A
=>cos2A=(cos²A-sin²A)/(cos²A+sin²A
Since {cos²A+sin²A=1}
Divide the numerator & the denominator by (cos²A) to get,
cos2A = {(cos²A-sin²A) ÷cos²A} / {(cos²A+sin²A) ÷cos²A}
cos2A ={(1-tan²A)/(1+tan²A)}
Then,
1-cos2A = 1-[{(1–tan²A)/(1+tan²A)}]
1-cos2A =(1+tan²A-1+tan²A)/(1+tan²A)
1-cos2A=(2tan²A)/(1+tan²A)
And now.......
1+cos2A=1+[{(1-tan²A)/(1+tan²A)}]
1+cos2A={1+tan²A+1-tan²A}/{1+tan²A}
1+cos2A=2/(1+tan²A)
So now,
(1-cos2A)/(1+cos2A)= {2tan²A/(1+tan²A)}÷{2/(1+tan²A)}
={(2tan²A)(1+tan²A)}÷{2(1+tan²A)}
=tan²A
Step-by-step explanation:
make me as brain liest
Answer:
603.2 meters
Step-by-step explanation:
circle - the outside of the walk in this case. This circle has a
diameter of 22 + 8 m, therefore a radius of 15m. The inner circle
has a diameter of 22m - as given - a radius of 11m.
You subtract the area of the inner circle from that of the larger circle.
Answer: Steepness
Decreasing the value b decreases the line’s
intersection with the y-axis
The hot tub takes in 1,520 watts everyday to keep its water warm. A kilowatt has 1,000 watts (hence kilo means 1,000). 1,520 divided by 1,000 equals 1.520. However, this isn't free electricity - Each kilowatt costs 8 cents or 0.08 of a dollar. 1.520 x 0.08 = 12.160 or $12.16. We aren't done yet! This hot tub runs for 4 months (and we are assuming these months exactly have 30 days each). 4 x 30 = 120. $12.16 x 120 = $1,459.20. In order to keep the hot tub running, you need to pay 1,459.20 for all the kilowatts of electricity it takes.
Answer: 4*3*4=48
(*) means multiplication in case you don't know.
Step-by-step explanation: When finding the volume of a rectangular prism or cube, you just multiply the length, width, and Height.
