Using the dot product:
For any vector x, we have
||x|| = √(x • x)
This means that
||w|| = √(w • w)
… = √((u + z) • (u + z))
… = √((u • u) + (u • z) + (z • u) + (z • z))
… = √(||u||² + 2 (u • z) + ||z||²)
We have
u = ⟨2, 12⟩ ⇒ ||u|| = √(2² + 12²) = 2√37
z = ⟨-7, 5⟩ ⇒ ||z|| = √((-7)² + 5²) = √74
u • z = ⟨2, 12⟩ • ⟨-7, 5⟩ = -14 + 60 = 46
and so
||w|| = √((2√37)² + 2•46 + (√74)²)
… = √(4•37 + 2•46 + 74)
… = √314 ≈ 17.720
Alternatively, without mentioning the dot product,
w = u + z = ⟨2, 12⟩ + ⟨-7, 5⟩ = ⟨-5, 17⟩
and so
||w|| = √((-5)² + 17²) = √314 ≈ 17.720
Answer:
-4 < n ≤ 5
Step-by-step explanation:
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You already know that y equals -4. It says that x equals 3, so multiply the -4 by 3 and because it has a negative number and a positive number it will equal -12. Remember anytime you see a letter after a number it means multiply. The complete problem should be -10 because 2 is a whole number you subtract it from -12. Hope that helped you out some.
Each kid ticket will cost 12.25 dollars because 18.50 times 12 equals 222 dollars. You subtract 222 from 344.50 to get the total amount for 10 kids which is 122.50 dollars. 122.50 divides by 10 is 12.50.
