Answer:
cos(theta/2) = sqrt((1+x)/2)
Step-by-step explanation:
From the double angle formula
cos^2(t)-sin^2(t) = cos(2t) ...................(1)
cos^2(x)+sin^2(x) = cos(t-t) =1...............(2)
Add (1) and (2)
2cos^2(t) = 1+cos(2t)
cos^2(t) = (1+cos(2t))/2
cos(t) = sqrt((1+cos(2t))/2)
substitute t = theta/2
cos(theta/2) = sqrt((1+cos(theta))/2)
substitute cos(theta) = x
cos(theta/2) = sqrt((1+x)/2)
50 degrees is one while the other two are 130 degrees
ok this one is tricky but I think I can handle it.
The correct answer is more than 60mph but less than 61mph.
60.3mph = 281.399598
or 60.2mph =280.932932
Those are my closest answers.
I really hope this helps
Answer:
Tara's current expression finds how much the school will be keeping. 50 x 2/5 (also written as 50 x 0.4) totals out as 20. $20 is 2/5 of $50. The expression that Tara SHOULD have written to find how much goes to the candle company would be 50 x 3/5 (also written as 50 x 0.6), as this adds up to 30. $30 is 3/5 of $50.
Step-by-step explanation:
50/5 = 10 which means that 1/5 of 50 = 10.
2/5 of 50 ($20) is kept by the school. This is what Tara's expression finds. This means that $30 is sent to the candle company, and can be found with the expression 50 x 3/5.
The decimals are created by dividing the numerator of the fraction by the denominator (I find it easier to do math with decimals).
