X²-9≥0 U x≠4
(x-3)(x+3)≥0
x=3 x=-3
x≤-3 U x≥3
x∈(-∞;-3] U [3;4) U (4;∞)
Sin(2П -x) = -sin(x) =1/2
-sinx = sin(-x)=1/2
X= -30°
<span>1) f(x)=2cosx*tgx = 2Сosx*Sinx/Cosx = 2Sinx
f'(x) = 2Cosx
2) f(x)=(x²-6x+5)²
f'(x) = 2(x</span>²-6x +5)*92x -6)
<span>(1.) 5a^2-20ab = 5a (a-4b)
</span><span>(2.) 3a-3b+ax-bx = 3(a-b) + x(a-b) = (a-b)(3+x)
</span><span>(3.) a^2-9 = (a-3)(a+3)
</span><span>4.) (a-2b)^2 = a^2 - 4ab +4b^2</span>