Answer:
Find sin 2x, knowing tan x = -2, and cos x > 0
Ans:
sin
2
x
=
4
5
Explanation:
3 Trig identities to be used:
1
+
tan
2
x
=
1
cos
2
x
(1)
sin
2
x
+
cos
2
x
=
1
(2)
sin
2
x
=
2
sin
x
.
cos
x
(3)
Given tan x = -2. First find cos x and sin x
(1) -->
1
+
4
=
1
cos
2
x
-->
cos
2
x
=
1
5
-->
cos
x
=
±
1
√
5
.
Since cos x > 0, then
cos
x
=
1
√
5
.
(2) -->
sin
2
x
=
1
−
cos
2
x
=
1
−
1
5
=
4
5
-->
sin
x
=
±
2
√
5
.
Since cos x > 0 then
sin
x
=
2
√
5
.
(3) -->
sin
2
x
=
2
sin
x
.
cos
x
=
2
(
1
√
5
)
(
2
√
5
)
=
4
5
Answer link
Since there is no x it’s simply moving down 4. There is no movement left or right (x) just simply down for -4.
<h3>
Answer:</h3>
B) (x + 7)^2 = 20
<h3>
Step-by-step explanation:</h3>
You can subtract 34 from the original equation to get
... x^2 +14x = -29
Now, you can add the square of half the x-coefficient, and you will have ...
... x^2 +14x +49 = -29 +49
... (x +7)^2 = 20 . . . . . . matches selection B
_____
<em>Comment on answer choice A</em>
The question asks for the form (x -p)^2 = q, but that does not mean that p must be positive. Here, p=-7 and q=20.
216/2= 108
108*3= 324 pages
There are 324 pages in the book.
I hope this helps!
~kaikers
Answer:
49-7x=21
Step-by-step explanation:
