Ответ:
1)
f(x)=7x-14, [0;4]
f(0)=7*0-14=-14 -min
f(3)=7*4-14=14 -max
2)
f(x)-0.2x+0.4 [1;3]
f'(x)=-0.2- не принадлежит [1;3]
f(1)=-0.2*3+0.4=-0.6+0.4=-0.2 -max
f(3)=-0.2*3+0.4=-0.6+0.4=-0.2 -min
3)
f(x)= 6/x, [1;6]
f'(x)=(6x^1)'=6*(1)x^1-1=6*x=6/x
6/x=0 x≠0
x≠0 -не проверяем
f(1)=6/1=6 -max
f(6)=6/6= 1-min
4)
f(x)= -5/x, [-5;-1]
f'(x)=(-5x^-1)'=-5*(-1)x^-1-1=5*x^-2=5/x^2
5/x=0 x^2≠0
x≠0- не проверяем
f(-5)=5/-5=1 -min
f(-1)=-5/-1=5 - max