X + x+1 + x + 2 = 20
3x + 3 = 20
3x = 17 but can't start with x = 6 because 6+7+8 > 20,
so have start with 5 + 6 + 7 = 18 are the 3 sides.
Answer:
π
2
,
3
⋅
π
2
,
3
⋅
π
4
,
7
⋅
π
4
Explanation:
Factorizing your equation we get
cot
(
x
)
=
0
so
cos
(
x
)
=
0
we get the following Solutions in the given interval
x
=
π
72
or
x
=
3
π
2
for the second case we get
cot
(
x
)
=
−
1
so
cos
(
x
)
=
−
sin
(
x
)
and we get
x
=
3
π
4
or
x
=
7
π
4
Hint:
To get the Solutions of the last equation you can use
√
sin
(
x
+
π
4
)
=
0
Step-by-step explanation:
3x - 9y = 9
-3x + 4y = -14
-5y = -5
y = 1
3x - 9(1) = 9
3x - 9 = 9
3x = 18
x = 6
So, the answer is (6, 1)