y`=2(x²+1)*2x-2*2x=4x³+4x-4x=4x³
y`(2)=4*8=32
f`(x))=1/4*1/cos²8x *8=2/cos²8x
f`(π/4)=2/cos²2π=2/1=2
f`(x)=4cos4x*cos4x-4sin4x*sin4x=4(cos²4x-sin²4x)=4cos8x
f`(π/3)=4cos8π/3=4cos2π/3=4*(-1/2)=-2
f`(x)=-2sin2x-√3=0
sin2x=-√3/2
2x=(-1)^n+1 *π/3+πn
x=(-1)^n+1 *π/6+πn/2
x=-π/3;-π/6;2π/3;5π/6
f`(x)=6cos6x-6sin6x=0
6(sin(π/2-6x)-sin6x)=0
2sin(π/4-6x)cosπ/4=0
sin(π/4-6x)=0
π/4-6x=πn
-6x=-π/4+πn
x=π/24+πn/6