U=600/t
t=600/u
------------------------------
<span>ab+3b-5a-15=(ab-5a)+(3b-15)=a(b-5)+3(b-5)=(b-5)(a+3)</span>
a) (y)'=8*x^7; б) (y)'=4*3*x^2+2*2X=12x^2+4x в)(y)'=2*4x^3+3=8x^3+3;
a) <span>f '(x)=-Sinx</span>
<span>f '(<span> π/2)=-Sin<span> π/2=-1</span></span></span>
<span><span><span>б) f '(x)=3x^2-4x</span></span></span>
<span><span><span> f '(4)=3*16-16=48-16=32</span></span></span>
в) f '(x)=1-3*2х^-3=1-6*x^-3
f '(0)=1-6*0=1-0=1