По формуле 1+тангенс²=1/кос²
кос=-0,32
=1/!/2×9 + 1/!/2=1/ 3!/2+1/ !/2=(1+3)/ 3!/2=
=4/3!/2
Sin57cos27+cos57sin27= sin(57 + 27) = sin(84) ≈ 0.99
sin57cos27-cos57sin27= sin(57 - 27) = sin(30) = 1/2
2sin 75*cos75= sin2*75 = sin150 = sin(180 - 30) = sin30 = 1/2
2sin 75 - cos75 = 2si + 45) – cos(30 + 45) = 2sin30cos45 + 2cos30sin45 – cos30cos45 + sin30sin45 = 2*(1/2)*(√2/2) + 2*(√3/2)*(√2/2) - (√3/2)*(√2/2) + (1/2)* (√2/2) = 3√2/4<span> - √6/4</span>
А)(√8-3)*(3+2√2)=3√8-9+2√8*√2-6√2=3√8-6√2+2√16-9=3√2*4 -6√2 +2√4*4-9=
=6√2-6√2+4√4-9=4*2-9=8-9=-1
б)(√50+4√2)*√2=√50*√2+4√2*√2=(√50*2)+4*2=(√100)+8=10+8=18
в)(5√3+√27)\√3=5√3\√3 +√27\√3=5+√(27\3)=5+√9=5+3=8
г) (√3-1)²+(√3+1)²=(√3)²-2√3+1+(√3)²+2√3+1=3+2+3=8