Question

What is the exact value of cos(7π/12)+cos(π/ 12)?

0

2√ 4

2√ 2

−2√ /2

Answer 1

use the formula\[\cos a+\cos b=\frac{1}{2} \cos \left(\frac{a+b}{2}\right) \cos \left(\frac{a-b}{2}\right)\]

Answer 2

i got the wrong answer i think i did it wrong i still dont understand

Answer 3

show me your steps please

Answer 4

i figured it out, i just did my steps wrong thank you

Answer 5

\[
2 \cos \left(\frac{1}{2} \left(\frac{7 \pi
}{12}+\frac{\pi }{12}\right)\right) \cos
\left(\frac{1}{2} \left(\frac{7 \pi
}{12}-\frac{\pi
}{12}\right)\right)=\frac{1}{\sqrt{2}}
\]
I did not get any choices. Have I done something wrong?

Answer 6

i got \[\frac{\sqrt{2}}{2}\]too !!

Answer 7

thats the answer!!