What is the value of \\cos 36^\\circ? (Hint: use \\sin 18^\\circ)
fracsqrt5+14\\frac{\\sqrt{5}+1}{4}fracsqrt5+14
fracsqrt5−14\\frac{\\sqrt{5}-1}{4}fracsqrt5−14
fracsqrt10+2sqrt54\\frac{\\sqrt{10+2\\sqrt{5}}}{4}fracsqrt10+2sqrt54
0.75