<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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Answer:
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Step-by-step explanation:
Required
Show that:
To make the proof easier, I've added a screenshot of the triangle.
We make use of alternate angles to complete the proof.
In the attached triangle, the two angles beside 
are alternate to 
and 
i.e.
Using angle on a straight line theorem, we have:
Substitute values for (1) and (2)
Rewrite as:
<em></em><em> -- proved</em>
Answer:
five times a number of pencils plus three pencils =twenty-eight pencils.
Step-by-step explanation:
x = 5, Have a great day!
