Пусть x^2=t, тогда:
4t^2-4t-15=0
D=16+4*15*4=256
t1=-3/2⇒не яв-ся решение
t2=5/2
x^2=5/2
x=±√5/2
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√96z² = 4z√6
√50t¹º = 5*(t^5) √2
<span>√m³/n³ = (m/n)*</span>√(m/n)
А1=105; d=7;
an=a1+d(n–1)=105+7n–7=98+7n
a78=546
S78=(а1+а78)/2•78=(105+546)/2•78=
=25389
f(x)' = (x^2/2x-1)' = ( (x^2)' (2x-1) -x^2*(2x-1)' ) / (2x-1)^2 =
= ( 2x (2x-1) - x^2*2 ) / (2x-1)^2 = ( 4x^2 -2x - 2 x^2 ) / (2x-1)^2 =
= ( 2x^2 -2x ) / (2x-1)^2 = 2x( x -1 ) / (2x-1)^2