Seems like there is a correction in the first question (RHS is tanx.tany)
(i) For convenience: let tanx = a ; tany = b
Thus, tanx + tany = a + b
Moreover, cotx = 1/tanx = 1/a ; coty = 1/b
Thus,
cotx + coty = 1/a + 1/b = (a + b)/ab
Hence,
=> (tanx + tany)/(cotx + coty)
=> (a + b) / { (a + b)/ab }
=> ab(a + b)/(a + b)
=> ab => tanx.tany , proved.
(ii) For convenience: let sinx = a ; cosx = b
As we know, sin²x + cos²x = 1 => a²+b²=1
=> (a³ + b³)/(a + b)
=> (a + b)(a² + b² - ab) / (a + b)
=> (a² + b² - ab)
=> 1 - ab => 1 - sinx.cosx , proved
(iii): let x/2 = A
=> tan(x/2) + cosx.tan(x/2)
=> tanA + cos2A.tanA
=> tanA [1 + cos2A]
=> tanA (2cos²A) {1+cos2A = 2cos²A}
=> (sinA/cosA) (2cos²A)
=> sinA (2cosA)
=> 2sinAcosA
=> sin2A
=> sin2(x/2)
=> sinx proved
Letting x/2 = A is not mandatory. I did it to decease words*(in a line).
<u>Indentities used</u>:
• sin²A + cos²A = 1
• (a³ + b³) = (a + b)(a² + b² - 1)
• 1 + cosA = 2 cos²(A/2)
• tanA = sinA/cosA.
• 2sinAcosA = sin2A
<h3>Answer: Approximately 191 bees</h3>
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Work Shown:
One way to express exponential form is to use
y = a*b^x
where 'a' is the initial value and 'b' is linked to the growth rate.
Since we're told 34 bees are there initially, we know a = 34.
Then after 4 days, we have 48 bees. So we can say,
y = a*b^x
y = 34*b^x
48 = 34*b^4
48/34 = b^4
24/17 = b^4
b^4 = 24/17
b = (24/17)^(1/4)
b = 1.090035
Which is approximate.
The function updates to
y = a*b^x
y = 34*(1.090035)^x
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As a way to check to see if we have the right function, plug in x = 0 and we find:
y = 34*(1.090035)^x
y = 34*(1.090035)^0
y = 34*(1)
y = 34
So there are 34 bees on day 0, ie the starting day.
Plug in x = 4
y = 34*(1.090035)^x
y = 34*(1.090035)^4
y = 34*1.4117629
y = 47.9999386
Due to rounding error we don't land on 48 exactly, but we can round to this value.
We see that after 4 days, there are 48 bees.
So we confirmed the correct exponential function.
------------------------
At this point we can find out how many bees there are expected to be after 20 days.
Plug in x = 20 to get
y = 34*(1.090035)^x
y = 34*(1.090035)^20
y = 190.672374978452
Round to the nearest whole number to get 191.
There are expected to be roughly 191 bees on day 20.
Answer:circles
Step-by-step explanation:
2230.80 per month
=2230.80/4 = 557.70 per week
=557.70/40 = 13.9452 per hour