Sin(225) = sin(180 + 45) = -sin(45) = - √2/2
tg(240) = tg(180 + 60) = tg(60) = √3
ctg(135) = ctg(180 - 45) = - ctg(45) = - 1
4+(34х-25)=35
4+34х-25=35
34х=35-4+25
34х=56
х=56/34
х=1 11/17
Y = 2x - 3
График данной функции - прямая
y(7) = 2 * 7 - 3 = 14 - 3 = 11
Строишь по точкам:
x1 = 0 y1 = 2 * 0 - 3 = -3
x2 = 1 y2 = 2 * 1 - 3 = -1