What is the value of cosine of open paren 15 degrees close paren ?
A
the fraction with numerator square root of 6 minus square root of 2 and denominator 4B
the fraction with numerator square root of 6 minus square root of 2 and denominator 2C
the fraction with numerator square root of 6 plus square root of 2 and denominator 2D
the fraction with numerator square root of 6 plus square root of 2 and denominator 4