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
The distance around the crater is the circumference.
The formula for circumference is pi x diameter.
C= pi x d
C= 3.14 x 3000
C= 9420 feet
9514 1404 393
Answer:
D. 7
Step-by-step explanation:
The equation is ...
x = a(y +1)² -3
For the point (x, y) = (4, 0), we have ...
4 = a(0 -1)² -3
7 = a . . . . . . . . . . . . add 3, simplify
The leading coefficient is 7.
Answer in the attachment.
Used:
