6*900-4*900=5400-3600=1800
10*700-8*700= 7000-5600=1400
17*800-10*800=13600-8000=5600
11*900-8*900=9900-7200=2700
12*400-6*400=4800-2400=2400
21*60-10*60=1260-600=660
2cos(2x-П/4)=1/2,
cos(2x-П/4)=1/4,
2x - П/4 = arccos(1/4) +,-2П*n,
2x = П/4 + arccos(1/4) +,-2П*n,
x = П/8 + 0,5*arccos(1/4) +,-П*n,
n = 0,1,2,3,...
2П*n - период.
---------------------------------------
ОТВЕТ:
x = 0,5*arccos(1/4) + П( 1/8 +,-n) ,
n = 0,1,2,3,...
<span>2П*n - период.</span>
2*5*9=10*9=90
5*4*3=20*3=60
5*6*7=30*7=210
4*5*5=20*5=100
5*2*8=10*8=80
5*4*6=20*6=120