Based on two different cases:
x
=
π
6
,
5
or
3
2
Look below for the explanation of these two cases.
Explanation:
Since,
cos
+
sin
1
we have:
−
So we can replace
in the equation
by
(
)
⇒
or,
0
using the quadratic formula:
b
±
√
4
a
c
for quadratic equation
⋅
8
9
Case I:
for the condition:
≤
to get positive value of
Case II:
to get negative value of
Answer link
Объяснение:
8x^3-1-8x^3-8x=3x+4
-1-8x=3x+4
-8x-3x=4+1
-11x=5
x= -5/11
(2x + 1)(4x^2 – 2x + 1) – 4x(2x^2 – 1) = 5x – 2
8x^3 +1 - 8x^3 +4x = 5x-2
1+4x = 5x- 2
4x-5x = -2 -1
-x = -3
x=3
(x – 1)^3 – x^2(x – 4) – (x + 2)(x – 2) = 0
x^3 - 3x^2 + 3x - 1^3 - x^3 + 4x^2 - (x^2-4)=0
x^3 - 3x^2 + 3x - 1^3 - x^3 + 4x^2 - x^2 + 4=0
0+3x+3=0
3x+3=0
3x=-3
x=-1
ps, дам объяснения как решал если нужно, только напиши
Добавил решение из коментария:
(x + 2)3 – x2(x + 5) – (x + 1)(x – 1) = 0
x^3 + 6x^2 + 12x +8 - x^3 - 5x^2 - (x^2-1) = 0
x^3 + 6x^2 + 12x +8 - x^3 - 5x^2 - x^2 + 1 = 0
0+12x+9=0
12x+9=0
12x=-9
x= - 9/12 = -3/4 = -0,75
Based on two different cases:
x
=
π
6
,
5
π
6
or
3
π
2
Look below for the explanation of these two cases.
Explanation:
Since,
cos
x
+
sin
2
x
=
1
we have:
cos
2
x
=
1
−
sin
2
x
So we can replace
cos
2
x
in the equation
1
+
sin
x
=
2
cos
2
x
by
(
1
−
sin
2
x
)
⇒
2
(
1
−
sin
2
x
)
=
sin
x
+
1
or,
2
−
2
sin
2
x
=
sin
x
+
1
or,
0
=
2
sin
2
x
+
sin
x
+
1
−
2
or,
2
sin
2
x
+
sin
x
−
1
=
0
using the quadratic formula:
x
=
−
b
±
√
b
2
−
4
a
c
2
a
for quadratic equation
a
x
2
+
b
x
+
c
=
0
we have:
sin
x
=
−
1
±
√
1
2
−
4
⋅
2
⋅
(
−
1
)
2
⋅
2
or,
sin
x
=
−
1
±
√
1
+
8
4
or,
sin
x
=
−
1
±
√
9
4
or,
sin
x
=
−
1
±
3
4
or,
sin
x
=
−
1
+
3
4
,
−
1
−
3
4
or,
sin
x
=
1
2
,
−
1
Case I:
sin
x
=
1
2
for the condition:
0
≤
x
≤
2
π
we have:
x
=
π
6
or
5
π
6
to get positive value of
sin
x
Case II:
sin
x
=
−
1
we have:
x
=
3
π
2
to get negative value of
sin
x
Answer link
Объяснение: