Х+37=3010×10
х+37=30100
х=30100 -37
х= 30063
1) (x-1)×(x+1)×(x-3)×(x+3)
2)x⁴+6x³+11x²+6x-120
3)x⁴+4x³+7x²+6x+3
<span>Let’s
call him N.
I don’t know the place he
was born but I exactly know that he was born in August.
N is my old friend and I look up to him.</span>
Whatever
he does, he does it well. Whether studying, doing creative works, or any other things.
<span><span>N
is not good at sport, but this fault is offset
by his good memory </span> and his strength. He can’t do many push-ups, but he can throw a ball really far.</span>
To
tell the truth, sometimes I envy him. But as N is my role model I try not to
think about the envy. I want to be like him.
<span>Despite the fact that N always
criticizes himself </span>I cant stop admiring him.
Чтобы был определен арккосинус, должно выполняться условие -1 ≤ 8x ≤ 1.
Если 8x < 0, то arccos 8x > π/2, но arctg принимает значения из промежутка (-π/2, π/2), поэтому равенство не возможно.
Значит, 0 ≤ x ≤ 1/8.
Обозначим arctg 3x = arccos 8x = a, тогда tg a = 3x, cos a = 8x.
Поскольку tg^2 a + 1 = 1/cos^2 a, должно выполняться следующее равенство:
9x^2 + 1 = 1/64x^2
9 * 64x^4 + 64x^2 - 1 = 0
36 * (2x)^4 + 16 * (2x)^2 - 1 = 0
Получилось уравнение, квадратное относительно t = (2x)^2, t ≥ 0:
36t^2 + 16t - 1 = 0
D/4 = 8^2 + 36 = 64 + 36 = 100 = 10^2
t = (-8 + 10)/36 = 1/18 (второй корень отрицательный)
(2x)^2 = 1/18 = 2/36
2x = (√2)/6 (второй корень отрицательный)
x = (√2)/12
<span>60 : 3 * 2 = 40 вроде так
</span>