Answer:
points
Step-by-step explanation:
Answer:
3 3/5 + 1 1/4 = <u>4 17/20</u>
7/8 + 1/12 =<u> 23/24</u>
8/9 - 2/5 = <u>22/45</u>
5 1/4 - 2 2/3 = <u>2 7/12</u>
Step-by-step explanation:
3 3/5 + 1 1/4
First convert into improper fractions
= 18/5 + 5/4
Now find the common denominator
72/20 + 25/20 =
97/20
Now simplify
4 17/20
<u>Next problem:</u>
7/8 + 1/12
find the common denominator
21/24 + 2/24 =
23/24
<u>Next problem:</u>
8/9 - 2/5
find the common denominator
40/45 - 18/45 =
22/45
<u>Next problem:</u>
5 1/4 - 2 2/3
First convert into improper fractions
21/4 - 8/3
find the common denominator
63/12 - 32/12 =
31/12
Now simplify
2 7/12
Answer:
558
Step-by-step explanation:
|266 + 292|
=> | 558 |
=> 558
(tan²(<em>θ</em>) cos²(<em>θ</em>) - 1) / (1 + cos(2<em>θ</em>))
Recall that
tan(<em>θ</em>) = sin(<em>θ</em>) / cos(<em>θ</em>)
so cos²(<em>θ</em>) cancels with the cos²(<em>θ</em>) in the tan²(<em>θ</em>) term:
(sin²(<em>θ</em>) - 1) / (1 + cos(2<em>θ</em>))
Recall the double angle identity for cosine,
cos(2<em>θ</em>) = 2 cos²(<em>θ</em>) - 1
so the 1 in the denominator also vanishes:
(sin²(<em>θ</em>) - 1) / (2 cos²(<em>θ</em>))
Recall the Pythagorean identity,
cos²(<em>θ</em>) + sin²(<em>θ</em>) = 1
which means
sin²(<em>θ</em>) - 1 = -cos²(<em>θ</em>):
-cos²(<em>θ</em>) / (2 cos²(<em>θ</em>))
Cancel the cos²(<em>θ</em>) terms to end up with
(tan²(<em>θ</em>) cos²(<em>θ</em>) - 1) / (1 + cos(2<em>θ</em>)) = -1/2
