Answer:
10
Step-by-step explanation:
You can first condense the series to make it simpler to study. If <em>n</em> is odd, then <em>n</em> = 2<em>k</em> - 1, and if <em>n</em> is even, then <em>n</em> = 2<em>k</em> for some <em>k</em> ≥ 1. So for each <em>k</em>, you can pair up the <em>k</em>-th terms of the odd- and even-indexed series.
odd:

even:

So the series can be re-indexed as

By the root test, the series converges, since
![\displaystyle\lim_{k\to\infty}\sqrt[k]{\left|\frac4{3^{k+1}}\right|}=\frac13\lim_{k\to\infty}\left(\frac43\right)^{\frac1k}=\frac13](https://tex.z-dn.net/?f=%5Cdisplaystyle%5Clim_%7Bk%5Cto%5Cinfty%7D%5Csqrt%5Bk%5D%7B%5Cleft%7C%5Cfrac4%7B3%5E%7Bk%2B1%7D%7D%5Cright%7C%7D%3D%5Cfrac13%5Clim_%7Bk%5Cto%5Cinfty%7D%5Cleft%28%5Cfrac43%5Cright%29%5E%7B%5Cfrac1k%7D%3D%5Cfrac13%3C1)
The area of triangle ABC from the given vertices is gotten as; 7.5
<h3>How to find the area of a triangle?</h3>
We are given the vertices of the triangle as;
A(1, 2)
B(4, 0)
C(1,-4)
The formula for area of a triangle with 3 vertices is;
Area = ¹/₂[x₁(y₂ - y₃) + x₂(y₃ - y₁) + x₃(y₁ - y₂)]
Thus;
Area = ¹/₂[1(0 + 4) + 4(-4 - 1) + 1(1 - 0)]
Area = ¹/₂(4 - 20 + 1)
Area = -7.5
Read more about area of triangle at; brainly.com/question/17335144
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