Ctg(t-π)=-3/4;π/2<t<π
π/2-π<t-π<π-π
-π/2<t-π<0
-ctg(π-t)=-3/4
-ctgt=-3/4
ctgt=-3/4
a)cos(3π/2-t)=-sint
1+ctg²t=1/sin²t
sin²t=1/(1+9/16)=16/25
sint=4/5
-sint=-4/5
b)cos(π+t)=-cost
cos²t=1-sin²t=1-16/25=9/25
cost=-3/5
-cost=3/5
(-1,7+(-2/3) * 0,3= (-1,7-2/3)* 0,3
Ответ:
Объяснение:
!!!!!!!!!!!!!!!!!!!!!!!!!!
=((√7-√2)²-(√7+√2)²)/((√7)²-(√2)²)=(7-2√14+2-7-2√14-2)/(7-2)=-4√14/5.
(-4√14)/5)²=16*14/25=224/25=8,96.