( Х - 1 )( Х + 3 ) = х( Х - 2 )
Х^2 + 3х - Х - 3 = х^2 - 2х
Х^2 + 2х - 3 = х^2 - 2х
2х + 2х = 3
4х = 3
Х = 0,75
A)sin(-1350) = sin (-3.360 - 270)=sin(-270) = - sin 270= -(-1)=1
b)cos 720= cos (2.360)=cos 0 = 1
c)tg 900= tg (5.180) = tg 0 = 0
d)cotg (-450) = cotg ( -360-90)=cotg (-90)=0
e)sin(19pí/6) = (12pí/6 + 7pí/6) = sin(7pí/6)=- 1/2
f)cos 11pí/2 = cos(8pí/2+3pí/2)=cos 3pí/2 = 0
g)tg 16pí/3 = tg (15pí/3 + pí/3)=tg pí/3 = odm. iz 3
h)cotg(-4/3pí) = cotg ( -3/3pí -1/3.pí) = cot (-1/3.pí)=- 1/3. odm. iz 3
2cos^2(x)-7cos(x)=2sin^2(x)
3а^2b • (-5а^3b)=-15a^5b^2
(2х^2у)^3=8x^6y^3
<span>(а + с)(а - с) - b(2а ) - (а - b + с) (а - b- с)= 0.
</span>a^2-c^2-2ab-a^2+ab+ac+ab-b2-cb-ac+bc+c^2=0
-2ху^2 • Зх^3у^5=-6x^4y^7
(-4аb^3<span>)^2=16a^2b^6</span>