3x-π/7=π/2+πn 3x=π/2+π/7+πn=π(1/2+1/7)+πn=9π/14+πn
x=3π/14+πn/3
S=a*b=40cm2
a=x
b=5/8x
x*5/8x=40
5*x2/8=40
x2=16
x=4
a=x=4cm
b=5/8x=5*4/8=20/8=5/2=2.5cm
1) f(x)=√(6x+7) x₀=3
f`(x)=6/(2/√(6x+7)
f(3)=6/(2*(√6*3+7))=6/(2*√25)=6/10=0,6.
2) f(x)=cos⁴x x₀=π/4
f`(x)=-4*cos³x*sinx
f`(π/4)=-4*cos²(π/4)*sin(π/4)=-4*(√2/2)³*(√2/2)=-4*(√2/2)⁴=-4*1/4=-1.
Надеюсь вы это имели ввиду