The price was $824.85 before the discount (yesterday)
Answer:
3 sin(41t) - 3 sin(t)
Step-by-step explanation:
The general formula to convert the product of the form cos(a)sin(b) into sum is:
cos(a) sin(b) = 0.5 [ sin(a+b) - sin (a-b) ]
The given product is:
6 cos(21t) sin(20t) = 6 [ cos(21t) sin(20t) ]
Comparing the given product with general product mentioned above, we get:
a = 21t and b = 20t
Using these values in the formula we get:
6 cos(21t) sin(20t) = 6 x 0.5 [ sin(21t+20t) - sin(21t-20t)]
= 3 [sin(41t) - sin(t)]
= 3 sin(41t) - 3 sin(t)
Therefore, second option gives the correct answer
The first option is greater.
<h3>
Answer: B) Only the first equation is an identity</h3>
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I'm using x in place of theta. For each equation, I'm only altering the left hand side.
Part 1
cos(270+x) = sin(x)
cos(270)cos(x) - sin(270)sin(x) = sin(x)
0*cos(x) - (-1)*sin(x) = sin(x)
0 + sin(x) = sin(x)
sin(x) = sin(x) ... equation is true
Identity is confirmed
---------------------------------
Part 2
sin(270+x) = -sin(x)
sin(270)cos(x) + cos(270)sin(x) = -sin(x)
-1*cos(x) + 0*sin(x) = -sin(x)
-cos(x) = -sin(x)
We don't have an identity. If the right hand side was -cos(x), instead of -sin(x), then we would have an identity.
Answer:
The bill before the tip was $13.75 if you add a 20% tip of $2.75 the total bill including the tip would be $16.50
The bill before the tip is $13.75
