to find the angle for cosine! vector products
<p>I am looking for an answer to find an angle-alpha for cosine. </p>

<pre><code>cos(alpha)=RT(vector).R(vector)/(modulus)RT(vector).(modulus)R(vector)
</code></pre>

<p>then I should need to find the angle alpha.</p>

<pre><code>public double dot1(double[] vectorA, double[] vectorB){
        double[] vecPro;
        vecPro = new double[2];
        vecPro[0] = vectorA[0]*vectorB[0];
        vecPro[1] = vectorA[1]*vectorB[1];
        return 0;
    }
</code></pre>

<p>this code is just an sample I did so far! for the dot product of <code>RT(vector).R(vector)</code>.
hmm is that correct that I did, because I am new to java language.</p>
