18) f '(x) = (-2)' * ctgx - (-2)* (ctgx)' = 0 * ctgx + 2 * (- 1/Sin²x) = - 2/Sin²x
19) f ' (x) = (Sin15x)' = Cos15x * (15x)' = 15Cos15x
20) f '(x) = [Cos(π/4 - 12x)] ' = - Sin(π/4 - 12x) * (π/4 - 12x)' = 12Sin(π/4 - 12x)
8 64 512 4096 32768. всее
1). x^2-8x=0
x(x-8)=0
x1=0; x2=8
2). 64-x^2=0
(8-x)(8+x)=0
x1=-8;x2=8
3).x^2-64=0
(x-8)(x+8)=0
x1=-8;x2=8
4).x^2-16=0
(x-4)(x+4)=0
x1=-4;x2=4