What is the value of cos2 15°?
Answer & explanation
Correct answer: option 2
cos15° = \(\frac{√3 + 1 }{2√2}\)
Now , cos2 15° = (\(\frac{√3 + 1 }{2√2}\))2
= \(\frac{3 + 1 + 2√3 }{8}\)
= \(\frac{4 + 2√3 }{8}\)
= \(\frac{2 + √3 }{4}\)
What is the value of cos2 15°?
Correct answer: option 2
cos15° = \(\frac{√3 + 1 }{2√2}\)
Now , cos2 15° = (\(\frac{√3 + 1 }{2√2}\))2
= \(\frac{3 + 1 + 2√3 }{8}\)
= \(\frac{4 + 2√3 }{8}\)
= \(\frac{2 + √3 }{4}\)