Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
14.3.5. Òðèãîíîìåòðè÷í³ ôóíêö³¿ ïîäâ³éíîãî, ïîëîâèííîãî<br />
òà ïîòð³éíîãî àðãóìåíò³â:<br />
2tgα<br />
1 tg<br />
α= α α= +<br />
2 α<br />
;<br />
sin 2 2sin cos<br />
1−tg<br />
α<br />
α= α− α= − α= α− = ; + α<br />
2<br />
cos 2<br />
2 2 2 2<br />
cos sin 1 2sin 2cos 1 1 tg<br />
2<br />
2tgα<br />
2<br />
tg2α= =<br />
2<br />
1−tg<br />
α ctgα−tgα<br />
;<br />
α 1−cosα α 1+ cosα<br />
sin = ; cos = ;<br />
2 2 2 2<br />
1 cos 1 cos<br />
tg<br />
α = − α ; ctg<br />
α =<br />
+ α<br />
2 1+ cosα 2 1−cosα ;<br />
α 1−cosα sinα<br />
tg = =<br />
2 sin α 1 + cos α ;<br />
α 1+ cosα sinα<br />
ctg = =<br />
2 sin α 1 − cos α ;<br />
2 2<br />
( ) ( )<br />
sin 3α= sin α 3−4sin α ; cos3α= cos α 4cos<br />
α−3 ;<br />
tg3 α= α− α α=<br />
α− α<br />
.<br />
3 3<br />
3tg tg ctg 3ctg<br />
; ctg3<br />
2 2<br />
1−3tg α 3ctg α−1<br />
14.3.6. Ôîðìóëè ïåðåòâîðåííÿ ñóìè (ð³çíèö³) òðèãîíîìåòðè÷íèõ<br />
ôóíêö³é ó äîáóòîê:<br />
x ± y x m y<br />
sin x ± sin y = 2sin cos ;<br />
2 2<br />
x + y x − y<br />
cos x + cos y = 2 cos cos ;<br />
2 2<br />
x + y x − y<br />
cos x − cos y = − 2 sin sin ;<br />
2 2<br />
( x ± y) sin ( y ± x)<br />
sin<br />
tg x ± tg y = ; ctg x ± ctg y = ;<br />
cos xcos y sin xsin<br />
y<br />
cos α+ sin α= 2cos( 45 o −α)<br />
;<br />
cos α−sin α= 2sin ( 45 o −α)<br />
;<br />
b<br />
a x+ b x = a + b ( x+ϕ)<br />
ϕ= a + b ≠<br />
a<br />
2 2 2 2<br />
sin cos sin ; tg , 0<br />
2<br />
+ 2 sin ( +ϕ)<br />
sin + cos<br />
b + atg<br />
x= a x b x = a b x<br />
cos x<br />
cos x<br />
2<br />
asin<br />
x+<br />
bcos<br />
x + 2 sin( +ϕ)<br />
a+ bctg<br />
x= = a b x ;<br />
sin x<br />
sin x<br />
b<br />
a<br />
ϕ= ϕ= a + b ≠<br />
a + b a + b<br />
2 2<br />
sin ; cos , 0<br />
2 2 2 2<br />
;<br />
;<br />
;<br />
498 499