7, 14, 21, 28, 35, 42, 49... 7 cars will need. to be washed to reach $49
X is 5. Hope this helps:)
Answer:
We have to prove
sin(α+β)-sin(α-β)=2 cos α sin β
We will take the left hand side to prove it equal to right hand side
So,
=sin(α+β)-sin(α-β) Eqn 1
We will use the following identities:
sin(α+β)=sin α cos β+cos α sin β
and
sin(α-β)=sin α cos β-cos α sin β
Putting the identities in eqn 1
=sin(α+β)-sin(α-β)
=[ sin α cos β+cos α sin β ]-[sin α cos β-cos α sin β ]
=sin α cos β+cos α sin β- sinα cos β+cos α sin β
sinα cosβ will be cancelled.
=cos α sin β+ cos α sin β
=2 cos α sin β
Hence,
sin(α+β)-sin(α-β)=2 cos α sin β
Answer:
a. (4, 13/6)
b. (4, -5/6)
c. (4, 5/6)
Step-by-step explanation:
sorry if it is not right.
Answer is b: 2.25
Explanation 2x2.25 =4.5
