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satela [25.4K]
3 years ago
11

Cos(a+b)cosb+ sin(a+b)sinb= cosa

Mathematics
1 answer:
Leviafan [203]3 years ago
8 0

Step-by-step explanation:

\cos \: (a + b) \: cos \: b +  \sin \: (a + b) \: sin \: b  \\ =  \cos \: a \\ LHS  \\ =  \cos \: (a + b) \: cos \: b +  \sin \: (a + b) \: sin \: b   \\  =  \cos \{(a + b) -  b \} \\  =  \cos (a + b-  b ) \\ =  \cos  \: a  \\  = RHS \\  \\ formula \: used \\  \cos \:a \: cos \: b +  \sin \: a \: sin \: b =  \cos(a - b)

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Write a number with two decimal places, that is bigger than 4 wholes and 1/5 but smaller than 4.25
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Answer :

11.45

step-by-step explantion :

4.25=17/4

when we add 41/5 and 17/4, we get

41×4+17×5/4×5

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3 years ago
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4 0
3 years ago
Which answer is a solution of the equation?
Nuetrik [128]

2x + y = 5

Put the coordinates of the points to the equation and check it:

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