<span>сos(α-β+π/2)+2sin(α+π)cos(β-π)=-sin(a-b)+2*(-sina)*(-cosb)=-sin(a-b)+2sinacosb=
=-sinacosb+cosasinb</span>+2sinacosb=<span>sinacosb+cosasinb=sin(a+b)</span>
4! * 3 = (1 * 2 * 3 * 4) * 4 = 24 * 4 = 96
(49b/a-25a/b)·1/7a+5b=7b-25/7a^2/b+5b=12b-25/7a^2/b
Решение
<span>Y=x^2+cosx в точке x0=П/2
y` = 2x - sinx
y`(</span><span>π/2) = 2*(π/2) - sin(π/2) = π - 1</span>