Answer:
8,5
Step-by-step explanation:
20,17,14,11,8,5,2,
Since both α and β are in the first quadrant, we know each of cos(α), sin(α), cos(β), and sin(β) are positive. So when we invoke the Pythagorean identity,
sin²(x) + cos²(x) = 1
we always take the positive square root when solving for either sin(x) or cos(x).
Given that cos(α) = √11/7 and sin(β) = √11/4, we find
sin(α) = √(1 - cos²(α)) = √38/7
cos(β) = √(1 - sin²(β)) = √5/4
Now, recall the sum identity for cosine,
cos(x + y) = cos(x) cos(y) - sin(x) sin(y)
It follows that
cos(α + β) = √11/7 × √5/4 - √38/7 × √11/4 = (√55 - √418)/28
Answer:
There's an app call ( m a t h w a y) that would give u the answer in sec
<h3>
Answer: Choice A) 212 square meters</h3>
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Explanation:
14.10 has four sig figs. The 0 at the end is significant. This measurement is accurate to the hundredths place. If the author wrote 14.1, then it would be accurate to the tenths place with three sig figs.
15.0 has three sig figs. The 0 is significant. If they wrote 15 or 15. then we'd be dealing with 2 sig figs instead; however they placed the 0 there to tell the reader "this measurement is accurate to the tenths place"
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Multiply the values given
14.10*15.0 = 211.5
Round that to three sig figs. We pick the smaller sig fig count to round to since we cannot be certain it is accurate to four sig figs. In a sense, we pick the weakest link and use that to determine rounding when it comes to multiplication and division.
This means 211.5 rounds to 212
