<p><a href="http://s4.postimg.org/vuu91edjx/image.jpg">http://s4.postimg.org/vuu91edjx/image.jpg</a></p>
<p><a href="http://s29.postimg.org/beq0lwjhz/image.jpg">http://s29.postimg.org/beq0lwjhz/image.jpg</a></p>
<p>Can u help me find the easiest way to solve these 2 questions </p>
<p>1.E
2.A</p>
<ol>
<li>Min(x^4 + x^2 - 4) = -4 at x=0. Note that x^4, x^2 are nonnegative for real x.</li>
</ol>
<p>Given y = -x^4 - 2x^3 + 5, y’ = -4x^3 - 6x^2, setting to zero yields critical points x = 0, -3/2. y(0) = 5, y(-3/2) = 107/16 and y has a global maximum, so max = 107/16. Difference = |107/16 - (-4)| = 171/16, which I got 10.7 rounded.</p>
<p>2.Rewrite numerator as 1 - cos^2 A = (1-cos A)(1 + cos A), cancel 1-cos A from top and bottom to get 1+cos A.</p>
<p>I don’t see an obvious solution to 1. without differentiation other than using a graphing calculator. Where is this problem from?</p>
<p>Miter94 thanks for explaination but can u explain the second one in more details , i didn’t get it clearly . My friend actually sent it for me. </p>
<p>sin^2 A + cos^2 A = 1, so sin^2 = 1 - cos^2 A</p>
<p>Rewrite 1 - cos^2 A as (1 - cos A)(1 + cos A)</p>
<p>Thaanks a lot </p>
