F`(x)=cosx-xsinx
f`(π/2)=cosπ/2-π/2*sinπ/2=0-π/2*1=-π/2
Y=2x-3 - прамая
m=-b/2a=-2/2*0=0
n=2*0-3=-3
<span>у=-3cos4х
y'=3sin4x </span>· (4x)'=12sin4x
A) -0,4²*2,5² = -1
б) 7ab-8cd+3ab-2cd = 10ab-10cd = (10*5*-0,4) - (10*0,6*15) = -20-90 = -110
в) -√-5²-2*-3 = -√-5²+6 = 5√6
г)4*3,5²-4*3,5+1 = 49-14+1 = 36