CUET Preparation Today
What is the value of cos2 15°? |
$(2+\sqrt{3})$ $\frac{(2+\sqrt{3})}{4}$ $\frac{(2+\sqrt{3})}{2}$ $\frac{(1+\sqrt{3})}{2}$ |
$\frac{(2+\sqrt{3})}{4}$ |
cos15° = \(\frac{√3 + 1 }{2√2}\) Now , cos2 15° = (\(\frac{√3 + 1 }{2√2}\))2 = \(\frac{3 + 1 + 2√3 }{8}\) = \(\frac{4 + 2√3 }{8}\) = \(\frac{2 + √3 }{4}\) |
