Practi 1 INVITING AND OFFERING
what
Complete the conversations.
would
see sugar time
are it let's like
A Would you like to come to a basketball match on Saturday?
9
B What?
A Hi John.
you hungry?
B No, but I
like a drink
А
would you like to drink?
B A coffee, please
A Milk and
?
B Just milk, please.
's the match?
's at 7.30. At the sports centre.
A
8 I'd love to. Thanks.
A Would you
B Yes, OK
А ОК, 6
you there.
3
to meet for a drink first?
meet at 6.30 in the bar,​

Сначала формулы . затем формулы двойного угла sin2α=2sinαcosα cos2α=cos²α-sin²α=cos²α-(1-cos²α)=2cos²α-1⇒  2cos²α=1+cos2α cos2α=cos²α-sin²α=1-sin²α-sin²α=1-2sin²α⇒  2sin²α=1-cos2α а) сos75°cos105°=cos(90°-15°)·cos(90°+15°)== sin15°(-sin15°)=-sin²15°=-(1-cos30°)/2=(cos30°-1)/2= ((√3/2)-1)/2=0,25√3-0,5б) sin75°sin15°=°sin(90°-15°)sin15°=cos15° sin15°=sin30°/2=1/4=0,25в) sin105°cos15°=sin(180°-75°)cos15°=sin75°cos15°=sin(90°-15°)cos15°=cos15°cos15°=(1+cos30°)/2=(1+(√3/2))/2=0,5 +0,25√3 2 способ формулы cosα·cosβ=0,5cos(α-β)+0,5cos(α+β) sinα·sinβ=0,5cos(α-β)-0,5cos(α+β) sinα·cosβ=0,5sin(α+β)+0,5sin(α-β) а) сos75°cos105°=0,5cos(75°-105°)+0,5cos(75°+105°)=0,5cos(-30°)+0,5 cos180°==0,5· √3/2+0,5·(-1)=0,25√3-0,5б) sin75°sin15°=0,5cos(75°-15°)-0,5cos(75°+15° )=0,5cos60°-0,5 cos90°=0,5·0,5=0,25в) sin105°cos15°=0,5sin(105°+15°)+0,5sin(105°-15°)= =0,5sin120°+0,5sin90°==0,5 sin(180°-60°)+0,5·1=0,5 sin 60°+0,5=0,25√3+0,5

Hello - hello  -what are you doing this weekend?   - nothing  - come with me to the computer club  - what is a "computer club"?   - if you love to play computer games, but you do not have a computer, you can play in a computer club.  - wow, this charge? - yes, but it does not require a lot of money  - good. what do i need to bring?   - if you learn well, then you can take the diary. for good learning are free to play   - can i call someone else?   - yes, of course   - i'll see you on saturday?   - well, goodbye  - goodbye