Answer:
The equation is given by:

Step-by-step explanation:
Sine function:
Has the following format:

In which A is the amplitude and
is the period.
Suppose you know the temperature is 80 degrees at midnight and the high and low temperature during the day are 89 and 71 degrees
This means that the amplitude of the sinusoidal variation function is 89 - 80 = 80 - 71 = 9. This means that 
During a 24-hour day, which means that the period is 24. So




So the variation is:

Assuming t is the number of hours since midnight, find an equation for the temperature, D, in terms of t.
Initial temperature of 80, so:

Answer:
X< 7/12
Step-by-step explanation:
<span>3down votefavorite1Find minimum and maximum value of function <span>f(x,y)=3x+4y+|x−y|</span> on circle<span>{(x,y):<span>x2</span>+<span>y2</span>=1}</span>I used polar coordinate system. So I have <span>x=cost</span> and <span>y=sint</span> where <span>t∈[0,2π)</span>.Then i exploited definition of absolute function and i got:<span>h(t)=<span>{<span><span>4cost+3sintt∈[0,<span>π4</span>]∪[<span>54</span>π,2π)</span><span>2cost+5sintt∈(<span>π4</span>,<span>54</span>π)</span></span></span></span>Hence i received following critical points (earlier i computed first derivative):<span>cost=±<span>45</span>∨cost=±<span>2<span>√29</span></span></span>Then i computed second derivative and after all i received that in <span>(<span>2<span>√29</span></span>,<span>5<span>√29</span></span>)</span> is maximum equal <span>√29</span> and in <span>(−<span>45</span>,−<span>35</span>)</span> is minimum equal <span>−<span>235</span></span><span>
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