А) (√2 +2)² =(√2)² + 2*2*√2+2² =2+4√2+4=6+4√2
б) (√5 -1)² = (√5)² - 2*1*√5 + 1² = 5 -2√5 + 1 =6 -2√5
в) (2+√17)²=2² +2*2*√17 + (√17)²=4 +4√17+17=21+4√17
г) (3-√8)²= 3² - 2*3*√8 +(√8)² = 9 -6√8+8 =17-6√8
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>
См. вложение
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