Answer:
Step-by-step explanation:
The correct question is
Use the given information to find the exact value of the expression. sin α = 21/29, α lies in quadrant II, and cos β = 15/17, β lies in quadrant I Find sin (α - β).
we know that
sin(α − β<span>) = </span>sin α cos β − cos α sin β
α lies in quadrant II
so
cos α is negative
sin α is positive
β lies in quadrant I
so
cos β is positive
sin β is positive
step 1
find sin β
cos β=15/17
sin² β+cos² β=1-----------> sin² β=1-cos² β----> sin² β=1-(15/17)²
sin² β=1-225/289-----> 64/289
sin β=8/17
step 2
find cos α
sin α = 21/29
cos² α + sin² α=1----> cos² α=1-sin² α---> cos² α=1-(21/29)²---> 1-441/841
cos² α=400/841------> cos α=-20/29 (remember cos α is negative)
step 3
find sin(α − β)
sin α = 21/29 cos α=-20/29
sin β=8/17 cos β=15/17
sin(α − β) = [21/29]*[15/17] − [-20/29*]*[8/17]
sin(α − β) = [315/493] − [-160/493]
sin(α − β) = 475/493
the answer is
sin(α − β) = 475/493
if you want to be sure :/
= 20
First, simplify
to
/ Your problem should look like:
= 20
Second, multiply both sides by 8. / Your problem should look like: -5c = 160
Third, divide both sides by -5. / Your problem should look like: c =
Fourth, simplify
to
/ Your problem should look like: c =
Fifth, simplify
to 32. / Your problem should look like: c = -32
Answer:
B) -32
[15 + 1/2 ] - [ 2 + 3/4 ] - [6 + 2/3 ]......convertng these to improper fractions, we have
[31 /2 ] - [11 / 4 ] - [ 20 / 3 ] getting a common denominator (12), we have
[186 / 12] - [33 / 12 ] - [ 80 / 12 ] = 73 / 12 inches = about 6.0833 inches left
