Trigonometri

1-cos108.cos36=? cevap:-1/4

2-sin Π/10.cos 4Π/5=? cevap:-1/4

3- cos Π/8.cos Π/16.cos Π/32.cos 15Π/32=? cevap:√2/16

4-cos Π/48.cos Π/24.cos Π/12.cos 23Π/48=? cevap:1/2

Yardımlarınız için şimdiden teşekkür ederim.

1)

cos108.cos36=(-sin18).cos36=

(-sin18).cos18.cos36

cos18

=

https://chart.apis.google.com/chart?...1%7D%7B4%7D%20

2)
https://chart.apis.google.com/chart?...ight)%5Cright)


https://chart.apis.google.com/chart?...1%7D%7B4%7D%20

3)
https://chart.apis.google.com/chart?...0%7D%7B2%7D%20


https://chart.apis.google.com/chart?...20%5Cright)%3D


https://chart.apis.google.com/chart?...20%5Cright)%3D


https://chart.apis.google.com/chart?...7D%20%5Cright)


https://chart.apis.google.com/chart?...7D%20%5Cright)


https://chart.apis.google.com/chart?...7D%20%5Cright)


https://chart.apis.google.com/chart?...%7D%7B16%7D%20

Hocam yardımlarınız için teşekkürler.Bu çözümlerde yarım açı formüllerinimi kullandıız?

Evet yarım açı formüllerinden:
sin2x=2.sinx.cosx

sinx.cosx=

1

2

.sin2x

.

4)
https://chart.apis.google.com/chart?...0%7D%7B2%7D%20


https://chart.apis.google.com/chart?...20%5Cright)%3D


https://chart.apis.google.com/chart?...20%5Cright)%3D


https://chart.apis.google.com/chart?...20%5Cright)%3D


https://chart.apis.google.com/chart?...7D%20%5Cright)


https://chart.apis.google.com/chart?...7D%20%5Cright)


https://chart.apis.google.com/chart?...7D%20%5Cright)


https://chart.apis.google.com/chart?...7D%20%5Cright)


https://chart.apis.google.com/chart?...%7D%7B16%7D%20