1
INPUT "x1="; x1
INPUT "y1="; y1
INPUT "x2="; x2
INPUT "y2="; y2
a = (x1 * x2 + y1 * y2) / (SQR(x1 * x1 + y1 * y1) * SQR(x2 * x2 + y2 * y2))
PRINT "cosA="; a
a = 3.14 / 2 - ATN(a / SQR(1 - a * a))
a = a * 180 / 3.14
PRINT "A="; a

2
INPUT "a="; a
INPUT "b="; b
INPUT "c="; c
d = b * b - 4 * a * c
IF d < 0 THEN
    PRINT "Корней нет"
ELSE
    IF d = 0 THEN
        PRINT "x="; -b / 2 / a
    ELSE
        PRINT "x1="; (-b - SQR(d)) / 2 / a
        PRINT "x2="; (-b + SQR(d)) / 2 / a
    END IF
END IF